diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 6d83d24aa..33a57a8c9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -66,7 +66,7 @@ jobs:
           mkdir -p $HOST_CCACHE_DIR
       - name: Build wheels (ARM)
         if: matrix.os == 'ubuntu-24.04-arm'
-        uses: pypa/cibuildwheel@v3.4.0
+        uses: pypa/cibuildwheel@v3.4.1
         env:
           # override the default CentOS “yum install … ccache” and drop ccache
           CIBW_BEFORE_ALL_LINUX: |
@@ -81,7 +81,7 @@ jobs:
 
       - name: Build wheels (all other platforms)
         if: matrix.os != 'ubuntu-24.04-arm'
-        uses: pypa/cibuildwheel@v3.4.0
+        uses: pypa/cibuildwheel@v3.4.1
         env:
           CIBW_BUILD: ${{ matrix.cibuild }}
           CIBW_ARCHS_MACOS: ${{ matrix.macos-arch }}
@@ -127,7 +127,7 @@ jobs:
         merge-multiple: true
         path: dist
 
-    - uses: pypa/gh-action-pypi-publish@v1.13.0
+    - uses: pypa/gh-action-pypi-publish@v1.14.0
       continue-on-error: true   # might fail if we don't bump the version
       with:
         user: __token__
@@ -144,7 +144,7 @@ jobs:
         merge-multiple: true
         path: dist
 
-    - uses: pypa/gh-action-pypi-publish@v1.13.0
+    - uses: pypa/gh-action-pypi-publish@v1.14.0
       with:
         user: __token__
         password: ${{ secrets.pypi_password }}
diff --git a/macbuild/build4mac_env.py b/macbuild/build4mac_env.py
index 363ab78c8..f09f8bbb4 100755
--- a/macbuild/build4mac_env.py
+++ b/macbuild/build4mac_env.py
@@ -328,7 +328,7 @@ RubyTahoe        = { 'exe':  '/System/Library/Frameworks/Ruby.framework/Versions
 #  install with 'sudo port install ruby34'
 # [Key Type Name] = 'MP34'
 Ruby34MacPorts  = { 'exe': '/opt/local/bin/ruby3.4',
-                    'inc': '/opt/local/include/ruby-3.4.8',
+                    'inc': '/opt/local/include/ruby-3.4.9',
                     'lib': '/opt/local/lib/libruby.3.4.dylib'
                   }
 
@@ -567,8 +567,8 @@ if _have_Homebrew_Python:
 # [4] KLayout executables including buddy tools
 #-----------------------------------------------------
 KLayoutExecs  = [ 'klayout' ]
-KLayoutExecs += [ 'strm2cif', 'strm2dxf', 'strm2gds', 'strm2gdstxt', 'strm2mag', 'strm2oas' ]
-KLayoutExecs += [ 'strm2txt', 'strmclip', 'strmcmp',  'strmrun',     'strmxor'  ]
+KLayoutExecs += [ 'strm2cif', 'strm2dxf', 'strm2gds', 'strm2gdstxt', 'strm2lstr', 'strm2mag' ]
+KLayoutExecs += [ 'strm2oas', 'strm2txt', 'strmclip', 'strmcmp',     'strmrun',   'strmxor'  ]
 
 #----------------
 # End of File
diff --git a/src/ant/ant/antService.cc b/src/ant/ant/antService.cc
index 74f9f4df6..fe45fbecb 100644
--- a/src/ant/ant/antService.cc
+++ b/src/ant/ant/antService.cc
@@ -1541,6 +1541,19 @@ Service::begin_move (lay::Editable::MoveMode mode, const db::DPoint &p, lay::ang
   }
 }
 
+static int snap_prio (lay::PointSnapToObjectResult::ObjectSnap os)
+{
+  if (os == lay::PointSnapToObjectResult::ObjectVertex) {
+    return 3;
+  } else if (os == lay::PointSnapToObjectResult::ObjectEdge) {
+    return 2;
+  } else if (os == lay::PointSnapToObjectResult::ObjectUnspecific) {
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
 void
 Service::snap_rulers (lay::angle_constraint_type ac)
 {
@@ -1566,7 +1579,7 @@ Service::snap_rulers (lay::angle_constraint_type ac)
     auto snp = snap2_details (org1, p1, ruler, ac);
     double dist = p1.distance (snp.snapped_point);
 
-    if (min_dist < 0 || dist < min_dist) {
+    if (min_dist < 0 || snap_prio (snp.object_snap) > snap_prio (min_snp.object_snap) || (snap_prio (snp.object_snap) == snap_prio (min_snp.object_snap) && dist < min_dist)) {
       min_snp = snp;
       min_dist = dist;
       min_delta = snp.snapped_point - p1;
@@ -1575,7 +1588,7 @@ Service::snap_rulers (lay::angle_constraint_type ac)
     snp = snap2_details (org2, p2, ruler, ac);
     dist = p2.distance (snp.snapped_point);
 
-    if (min_dist < 0 || dist < min_dist) {
+    if (min_dist < 0 || snap_prio (snp.object_snap) > snap_prio (min_snp.object_snap) || (snap_prio (snp.object_snap) == snap_prio (min_snp.object_snap) && dist < min_dist)) {
       min_snp = snp;
       min_dist = dist;
       min_delta = snp.snapped_point - p2;
@@ -1631,10 +1644,10 @@ Service::move (const db::DPoint &p, lay::angle_constraint_type ac)
 
     m_trans = db::DTrans (dp + (m_p1 - db::DPoint ()) - m_trans.disp ()) * m_trans * db::DTrans (db::DPoint () - m_p1);
 
-    propose_move_transformation (m_trans, 1);
-
     snap_rulers (ac_eff);
 
+    propose_move_transformation (m_trans, 1);
+
     for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
       (*r)->transform_by (db::DCplxTrans (m_trans));
     }
@@ -1834,6 +1847,7 @@ Service::edit_cancel ()
     m_move_mode = MoveNone;
     m_selected.clear ();
     selection_to_view ();
+    clear_mouse_cursors ();
 
   }
 }
diff --git a/src/db/db/dbEdgePairs.cc b/src/db/db/dbEdgePairs.cc
index cd43514b8..de4b3ab24 100644
--- a/src/db/db/dbEdgePairs.cc
+++ b/src/db/db/dbEdgePairs.cc
@@ -103,6 +103,13 @@ EdgePairs::EdgePairs (DeepShapeStore &dss)
   mp_delegate = new DeepEdgePairs (DeepLayer (&dss, layout_index, dss.layout (layout_index).insert_layer ()));
 }
 
+void
+EdgePairs::convert_to_deep (const db::DeepLayer &layer)
+{
+  tl_assert (mp_delegate->deep () == 0);
+  set_delegate (copy_data_id (new db::DeepEdgePairs (layer)));
+}
+
 void
 EdgePairs::write (const std::string &fn) const
 {
diff --git a/src/db/db/dbEdgePairs.h b/src/db/db/dbEdgePairs.h
index 7b2b4ed7f..f75d7d773 100644
--- a/src/db/db/dbEdgePairs.h
+++ b/src/db/db/dbEdgePairs.h
@@ -204,6 +204,11 @@ public:
    */
   explicit EdgePairs (DeepShapeStore &dss);
 
+  /**
+   *  @brief Converts the shape collection to a deep one using the specified layer
+   */
+  virtual void convert_to_deep (const db::DeepLayer &layer);
+
   /**
    *  @brief Writes the edge pair collection to a file
    *
diff --git a/src/db/db/dbEdges.cc b/src/db/db/dbEdges.cc
index 1cad75949..f64d23747 100644
--- a/src/db/db/dbEdges.cc
+++ b/src/db/db/dbEdges.cc
@@ -114,6 +114,13 @@ Edges::Edges (DeepShapeStore &dss)
   mp_delegate = new DeepEdges (DeepLayer (&dss, layout_index, dss.layout (layout_index).insert_layer ()));
 }
 
+void
+Edges::convert_to_deep (const db::DeepLayer &layer)
+{
+  tl_assert (mp_delegate->deep () == 0);
+  set_delegate (copy_data_id (new db::DeepEdges (layer)));
+}
+
 const db::RecursiveShapeIterator &
 Edges::iter () const
 {
diff --git a/src/db/db/dbEdges.h b/src/db/db/dbEdges.h
index ff8007d19..a12d09c58 100644
--- a/src/db/db/dbEdges.h
+++ b/src/db/db/dbEdges.h
@@ -264,6 +264,11 @@ public:
    */
   explicit Edges (DeepShapeStore &dss);
 
+  /**
+   *  @brief Converts the shape collection to a deep one using the specified layer
+   */
+  virtual void convert_to_deep (const db::DeepLayer &layer);
+
   /**
    *  @brief Implementation of the ShapeCollection interface
    */
diff --git a/src/db/db/dbLayoutUtils.cc b/src/db/db/dbLayoutUtils.cc
index 2a71a0c1a..5809458de 100644
--- a/src/db/db/dbLayoutUtils.cc
+++ b/src/db/db/dbLayoutUtils.cc
@@ -218,6 +218,7 @@ copy_or_propagate_shapes (db::Layout &target,
 
     db::Cell &target_cell = target.cell (cm->second);
     transformer->insert_transformed (target_cell.shapes (target_layer), source_cell.shapes (source_layer), trans * propagate_trans);
+
   }
 }
 
diff --git a/src/db/db/dbLibraryProxy.cc b/src/db/db/dbLibraryProxy.cc
index 84317d341..b1c24f2bb 100644
--- a/src/db/db/dbLibraryProxy.cc
+++ b/src/db/db/dbLibraryProxy.cc
@@ -244,7 +244,11 @@ LibraryProxy::update (db::ImportLayerMapping *layer_mapping)
 
     inst.transform_into (db::ICplxTrans (lib->layout ().dbu () / layout ()->dbu ()));
 
-    insert (inst);
+    if (i->has_prop_id ()) {
+      insert (db::CellInstArrayWithProperties (inst, i->prop_id ()));
+    } else {
+      insert (inst);
+    }
 
   }
 }
diff --git a/src/db/db/dbNetlistDeviceExtractor.cc b/src/db/db/dbNetlistDeviceExtractor.cc
index 1eb73b68f..9424007b8 100644
--- a/src/db/db/dbNetlistDeviceExtractor.cc
+++ b/src/db/db/dbNetlistDeviceExtractor.cc
@@ -130,8 +130,10 @@ void NetlistDeviceExtractor::extract (db::DeepShapeStore &dss, unsigned int layo
 
       std::pair<bool, db::DeepLayer> alias = dss.layer_for_flat (tl::id_of (l->second->get_delegate ()));
       if (alias.first) {
-        //  use deep layer alias for a given flat one (if found)
-        layers.push_back (alias.second.layer ());
+        //  use deep layer alias for a given flat one (if found) and convert layer to a deep one
+        db::DeepLayer dl = alias.second;
+        l->second->convert_to_deep (dl);
+        layers.push_back (dl.layer ());
       } else {
         throw tl::Exception (tl::sprintf (tl::to_string (tr ("Invalid region passed to input layer '%s' for device extraction (device %s): must be of deep region kind")), ld->name, name ()));
       }
diff --git a/src/db/db/dbPolygon.h b/src/db/db/dbPolygon.h
index 5835c0976..8ecadc16e 100644
--- a/src/db/db/dbPolygon.h
+++ b/src/db/db/dbPolygon.h
@@ -1581,7 +1581,7 @@ public:
   void translate (const polygon<C> &d, const T &t, db::generic_repository<C> &, db::ArrayRepository &)
   {
     *this = d;
-    transform (t);
+    transform (t, false);
   }
 
   /**
diff --git a/src/db/db/dbRegion.cc b/src/db/db/dbRegion.cc
index f290b87d3..8e40874fd 100644
--- a/src/db/db/dbRegion.cc
+++ b/src/db/db/dbRegion.cc
@@ -132,6 +132,13 @@ Region::Region (DeepShapeStore &dss)
   mp_delegate = new db::DeepRegion (db::DeepLayer (&dss, layout_index, dss.layout (layout_index).insert_layer ()));
 }
 
+void
+Region::convert_to_deep (const db::DeepLayer &layer)
+{
+  tl_assert (mp_delegate->deep () == 0);
+  set_delegate (copy_data_id (new db::DeepRegion (layer)));
+}
+
 void
 Region::write (const std::string &fn) const
 {
diff --git a/src/db/db/dbRegion.h b/src/db/db/dbRegion.h
index 655462a01..3a230fdf1 100644
--- a/src/db/db/dbRegion.h
+++ b/src/db/db/dbRegion.h
@@ -256,6 +256,11 @@ public:
    */
   void write (const std::string &fn) const;
 
+  /**
+   *  @brief Converts the shape collection to a deep one using the specified layer
+   */
+  virtual void convert_to_deep (const db::DeepLayer &layer);
+
   /**
    *  @brief Implementation of the ShapeCollection interface
    */
diff --git a/src/db/db/dbShapeCollection.h b/src/db/db/dbShapeCollection.h
index a03c008b2..0f48ffef9 100644
--- a/src/db/db/dbShapeCollection.h
+++ b/src/db/db/dbShapeCollection.h
@@ -75,7 +75,12 @@ class DB_PUBLIC ShapeCollectionDelegateBase
   : public tl::UniqueId
 {
 public:
-  ShapeCollectionDelegateBase () { }
+  ShapeCollectionDelegateBase ()
+    : m_data_id (tl::id_of (this))
+  {
+    //  .. nothing yet ..
+  }
+
   virtual ~ShapeCollectionDelegateBase () { }
 
   virtual DeepShapeCollectionDelegateBase *deep () { return 0; }
@@ -88,6 +93,22 @@ public:
       apply_property_translator (db::PropertiesTranslator::make_remove_all ());
     }
   }
+
+  tl::id_type data_id () const
+  {
+    return m_data_id;
+  }
+
+private:
+  friend class ShapeCollection;
+
+  tl::id_type m_data_id;
+
+  //  used for conversion to deep
+  void set_data_id (tl::id_type data_id)
+  {
+    m_data_id = data_id;
+  }
 };
 
 /**
@@ -102,6 +123,11 @@ public:
 
   virtual ShapeCollectionDelegateBase *get_delegate () const = 0;
 
+  /**
+   *  @brief Converts the shape collection to a deep one using the specified layer
+   */
+  virtual void convert_to_deep (const db::DeepLayer &layer) = 0;
+
   /**
    *  @brief Applies a PropertyTranslator
    *
@@ -111,6 +137,14 @@ public:
    *  delivered by "properties_repository".
    */
   void apply_property_translator (const db::PropertiesTranslator &pt);
+
+protected:
+  template <class Delegate>
+  Delegate *copy_data_id (Delegate *dlg)
+  {
+    dlg->set_data_id (get_delegate ()->data_id ());
+    return dlg;
+  }
 };
 
 }
diff --git a/src/db/db/dbTexts.cc b/src/db/db/dbTexts.cc
index 902a5cf2e..1e15801ed 100644
--- a/src/db/db/dbTexts.cc
+++ b/src/db/db/dbTexts.cc
@@ -99,6 +99,13 @@ Texts::Texts (DeepShapeStore &dss)
   mp_delegate = new DeepTexts (DeepLayer (&dss, layout_index, dss.layout (layout_index).insert_layer ()));
 }
 
+void
+Texts::convert_to_deep (const db::DeepLayer &layer)
+{
+  tl_assert (mp_delegate->deep () == 0);
+  set_delegate (copy_data_id (new db::DeepTexts (layer)));
+}
+
 void
 Texts::write (const std::string &fn) const
 {
diff --git a/src/db/db/dbTexts.h b/src/db/db/dbTexts.h
index 74441be07..276f9b415 100644
--- a/src/db/db/dbTexts.h
+++ b/src/db/db/dbTexts.h
@@ -208,6 +208,11 @@ public:
    */
   void write (const std::string &fn) const;
 
+  /**
+   *  @brief Converts the shape collection to a deep one using the specified layer
+   */
+  virtual void convert_to_deep (const db::DeepLayer &layer);
+
   /**
    *  @brief Implementation of the ShapeCollection interface
    */
diff --git a/src/db/db/gsiDeclDbEdgePairs.cc b/src/db/db/gsiDeclDbEdgePairs.cc
index 0ea5564f0..5a865399a 100644
--- a/src/db/db/gsiDeclDbEdgePairs.cc
+++ b/src/db/db/gsiDeclDbEdgePairs.cc
@@ -630,9 +630,9 @@ static bool is_deep (const db::EdgePairs *ep)
   return dynamic_cast<const db::DeepEdgePairs *> (ep->delegate ()) != 0;
 }
 
-static size_t id (const db::EdgePairs *ep)
+static size_t data_id (const db::EdgePairs *ep)
 {
-  return tl::id_of (ep->delegate ());
+  return ep->delegate ()->data_id ();
 }
 
 static db::EdgePairs filtered (const db::EdgePairs *r, const gsi::EdgePairFilterBase *f)
@@ -1114,7 +1114,7 @@ Class<db::EdgePairs> decl_EdgePairs (decl_dbShapeCollection, "db", "EdgePairs",
     "\n"
     "This method has been added in version 0.26."
   ) +
-  method_ext ("data_id", &id,
+  method_ext ("data_id", &data_id,
     "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
     "\n"
     "This method has been added in version 0.26."
diff --git a/src/db/db/gsiDeclDbEdges.cc b/src/db/db/gsiDeclDbEdges.cc
index a434a7d60..667878d62 100644
--- a/src/db/db/gsiDeclDbEdges.cc
+++ b/src/db/db/gsiDeclDbEdges.cc
@@ -892,9 +892,9 @@ static db::Edges *new_texts_as_dots2 (const db::RecursiveShapeIterator &si, db::
   return new db::Edges (db::Region (si).texts_as_dots (pat, pattern, dss));
 }
 
-static size_t id (const db::Edges *e)
+static size_t data_id (const db::Edges *e)
 {
-  return tl::id_of (e->delegate ());
+  return e->delegate ()->data_id ();
 }
 
 static std::vector<db::Edges> andnot_with_edges (const db::Edges *r, const db::Edges &other)
@@ -2572,7 +2572,7 @@ Class<db::Edges> decl_Edges (decl_dbShapeCollection, "db", "Edges",
     "\n"
     "This method has been added in version 0.26."
   ) +
-  method_ext ("data_id", &id,
+  method_ext ("data_id", &data_id,
     "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
     "\n"
     "This method has been added in version 0.26."
diff --git a/src/db/db/gsiDeclDbRegion.cc b/src/db/db/gsiDeclDbRegion.cc
index 528342e4a..de29f6ba7 100644
--- a/src/db/db/gsiDeclDbRegion.cc
+++ b/src/db/db/gsiDeclDbRegion.cc
@@ -1288,9 +1288,9 @@ static bool is_deep (const db::Region *region)
   return dynamic_cast<const db::DeepRegion *> (region->delegate ()) != 0;
 }
 
-static size_t id (const db::Region *r)
+static size_t data_id (const db::Region *r)
 {
-  return tl::id_of (r->delegate ());
+  return r->delegate ()->data_id ();
 }
 
 
@@ -4214,7 +4214,7 @@ Class<db::Region> decl_Region (decl_dbShapeCollection, "db", "Region",
     "\n"
     "This method has been added in version 0.26."
   ) +
-  method_ext ("data_id", &id,
+  method_ext ("data_id", &data_id,
     "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
     "\n"
     "This method has been added in version 0.26."
diff --git a/src/db/db/gsiDeclDbTexts.cc b/src/db/db/gsiDeclDbTexts.cc
index 22209b412..21f04d888 100644
--- a/src/db/db/gsiDeclDbTexts.cc
+++ b/src/db/db/gsiDeclDbTexts.cc
@@ -477,9 +477,9 @@ static bool is_deep (const db::Texts *t)
   return dynamic_cast<const db::DeepTexts *> (t->delegate ()) != 0;
 }
 
-static size_t id (const db::Texts *t)
+static size_t data_id (const db::Texts *t)
 {
-  return tl::id_of (t->delegate ());
+  return t->delegate ()->data_id ();
 }
 
 static db::Texts filtered (const db::Texts *r, const gsi::TextFilterBase *f)
@@ -686,7 +686,7 @@ Class<db::Texts> decl_Texts (decl_dbShapeCollection, "db", "Texts",
   method_ext ("is_deep?", &is_deep,
     "@brief Returns true if the edge pair collection is a deep (hierarchical) one\n"
   ) +
-  method_ext ("data_id", &id,
+  method_ext ("data_id", &data_id,
     "@brief Returns the data ID (a unique identifier for the underlying data storage)\n"
   ) +
   method ("+|join", &db::Texts::operator+, gsi::arg ("other"),
diff --git a/src/db/unit_tests/dbLayoutTests.cc b/src/db/unit_tests/dbLayoutTests.cc
index d7a503335..9b6178ca8 100644
--- a/src/db/unit_tests/dbLayoutTests.cc
+++ b/src/db/unit_tests/dbLayoutTests.cc
@@ -1009,3 +1009,34 @@ TEST(100_UndoOfDeleteLayer)
   EXPECT_EQ (l.get_properties (li).to_string (), "1/0");
   EXPECT_EQ (l.get_properties (li2).to_string (), "2/0");
 }
+
+//  issue #2343
+TEST(101_CopyTreeDoesNotModifyPolygons)
+{
+  db::Manager m;
+  db::Layout l (&m);
+  db::Cell &top = l.cell (l.add_cell ("TOP"));
+  l.insert_layer (db::LayerProperties (1, 0));
+
+  std::unique_ptr<db::Layout> t (new db::Layout ());
+  db::Cell &ttop = t->cell (t->add_cell ("TOP"));
+  unsigned int tl1 = t->insert_layer (db::LayerProperties (1, 0));
+
+  std::vector<db::Point> pts = {
+    { 0, 0 }, { 0, 1000 }, { 500, 1000 }, { 1500, 1000 }, { 1000, 1000 }, { 1000, 0 }
+  };
+
+  db::Polygon poly;
+  poly.assign_hull (pts.begin (), pts.end (), false /*don't compress*/, false /*don't remove reflected*/);
+  ttop.shapes (tl1).insert (poly);
+
+  EXPECT_EQ (l2s (*t), "begin_lib 0.001\nbegin_cell {TOP}\nboundary 1 0 {0 0} {0 1000} {500 1000} {1500 1000} {1000 1000} {1000 0} {0 0}\nend_cell\nend_lib\n");
+
+  db::CellMapping cm;
+  cm.create_single_mapping (l, top.cell_index (), *t, ttop.cell_index ());
+  l.copy_tree_shapes (*t, cm);
+
+  //  polygon is still not normalized
+  EXPECT_EQ (l2s (l), "begin_lib 0.001\nbegin_cell {TOP}\nboundary 1 0 {0 0} {0 1000} {500 1000} {1500 1000} {1000 1000} {1000 0} {0 0}\nend_cell\nend_lib\n");
+}
+
diff --git a/src/db/unit_tests/dbLibrariesTests.cc b/src/db/unit_tests/dbLibrariesTests.cc
index 70f1fba5c..e3bb44f8b 100644
--- a/src/db/unit_tests/dbLibrariesTests.cc
+++ b/src/db/unit_tests/dbLibrariesTests.cc
@@ -34,6 +34,7 @@
 #include "dbTestSupport.h"
 #include "dbFileBasedLibrary.h"
 #include "dbColdProxy.h"
+#include "dbTextWriter.h"
 #include "tlStream.h"
 #include "tlStaticObjects.h"
 #include "tlUnitTest.h"
@@ -861,3 +862,64 @@ TEST(7_monsterlib)
   //  but the layout did not change
   db::compare_layouts (_this, layout, tl::testsrc () + "/testdata/libman/design_au5.gds", db::NormalizationMode (db::NoNormalization | db::WithoutCellNames | db::AsPolygons));
 }
+
+namespace {
+
+class PCellWithChildDeclaration :
+  public db::PCellDeclaration
+{
+  void produce (const db::Layout &layout, const std::vector<unsigned int> & /*layer_ids*/, const db::pcell_parameters_type & /*parameters*/, db::Cell &cell) const
+  {
+    auto cid = const_cast<db::Layout &> (layout).add_cell ("CHILD");
+
+    db::PropertiesSet ps;
+    ps.insert ("id", tl::Variant ("my_id"));
+
+    auto ps_id = db::properties_id (ps);
+    cell.insert (db::CellInstArrayWithProperties (db::CellInstArray (cid, db::Trans ()), ps_id));
+  }
+};
+
+}
+
+static std::string l2s (const db::Layout &layout)
+{
+  tl::OutputStringStream os;
+  tl::OutputStream ostream (os);
+  db::TextWriter writer (ostream);
+  writer.write (layout);
+  return os.string ();
+}
+
+//  PCells with subcells with properties
+TEST(8_issue2344)
+{
+  std::unique_ptr<db::Library> lib (new db::Library ());
+  lib->set_name ("__PCellLibrary");
+  lib->layout ().register_pcell ("PCell1", new PCellWithChildDeclaration ());
+  db::LibraryManager::instance ().register_lib (lib.get ());
+
+  db::Layout ly;
+  std::pair<bool, db::pcell_id_type> pc = lib->layout ().pcell_by_name ("PCell1");
+  tl_assert (pc.first);
+
+  db::cell_index_type lib_cell = lib->layout ().get_pcell_variant_dict (pc.second, std::map<std::string, tl::Variant> ());
+  ly.get_lib_proxy (lib.get (), lib_cell);
+
+  EXPECT_EQ (l2s (ly),
+    "begin_lib 0.001\n"
+    "begin_cell {CHILD}\n"
+    "end_cell\n"
+    "begin_cell {PCell1}\n"
+    "set props {\n"
+    "  {{id} {my_id}}\n"
+    "}\n"
+    "srefp $props {CHILD} 0 0 1 {0 0}\n"
+    "end_cell\n"
+    "end_lib\n"
+  );
+
+  db::LibraryManager::instance ().delete_lib (lib.release ());
+  EXPECT (true);
+}
+
diff --git a/src/drc/drc/built-in-macros/_drc_netter.rb b/src/drc/drc/built-in-macros/_drc_netter.rb
index e5ec8f0a2..75506aae2 100644
--- a/src/drc/drc/built-in-macros/_drc_netter.rb
+++ b/src/drc/drc/built-in-macros/_drc_netter.rb
@@ -323,7 +323,9 @@ module DRC
     # 
     # If layers are not named, they will be given a name made from the 
     # \name_prefix and an incremental number when the layer is used for the
-    # first time. 
+    # first time. As the default name prefix is "l", you may can name conflicts
+    # with auto-named layers, if you register explicit layer names like "l5". 
+    # Consider changing the name prefix in that case to some prefix you are not using.
     #
     # \name can only be used once on a layer and the layer names must be 
     # unique (not taken by another layer).
diff --git a/src/img/img/imgObject.cc b/src/img/img/imgObject.cc
index 6642ccdcb..4f6d97cf3 100644
--- a/src/img/img/imgObject.cc
+++ b/src/img/img/imgObject.cc
@@ -1009,6 +1009,7 @@ Object::operator= (const img::Object &d)
 
     m_trans = d.m_trans;
     m_filename = d.m_filename;
+    m_tag = d.m_tag;
 
     mp_data = d.mp_data;
     if (mp_data) {
@@ -1963,6 +1964,7 @@ void
 Object::swap (Object &other)
 {
   m_filename.swap (other.m_filename);
+  m_tag.swap (other.m_tag);
   std::swap (m_trans, other.m_trans);
   std::swap (mp_data, other.mp_data);
   std::swap (m_id, other.m_id);
@@ -1979,6 +1981,12 @@ Object::swap (Object &other)
   std::swap (m_updates_enabled, other.m_updates_enabled);
 }
 
+void
+Object::set_tag (const std::string &tag)
+{
+  m_tag = tag;
+}
+
 size_t 
 Object::width () const
 {
diff --git a/src/img/img/imgObject.h b/src/img/img/imgObject.h
index a48e72551..6658d2ae9 100644
--- a/src/img/img/imgObject.h
+++ b/src/img/img/imgObject.h
@@ -581,6 +581,22 @@ public:
     return d;
   }
 
+  /**
+   *  @brief Sets the tag string
+   *
+   *  The tag string is an arbitrary string that can be used to identify
+   *  the image. It is not persisted and it not considered for equality or sorting.
+   */
+  void set_tag (const std::string &tag);
+
+  /**
+   *  @brief Gets the tag string
+   */
+  const std::string tag () const
+  {
+    return m_tag;
+  }
+
   /**
    *  @brief Accessor to the width property
    */
@@ -1036,6 +1052,7 @@ protected:
 
 private:
   std::string m_filename;
+  std::string m_tag;
   db::Matrix3d m_trans;
   DataHeader *mp_data;
   size_t m_id;
diff --git a/src/img/img/imgPropertiesPage.cc b/src/img/img/imgPropertiesPage.cc
index cdb14e1d1..83938a4d8 100644
--- a/src/img/img/imgPropertiesPage.cc
+++ b/src/img/img/imgPropertiesPage.cc
@@ -314,46 +314,48 @@ PropertiesPage::min_max_value_changed ()
   emit edited ();
 }
 
+bool
+PropertiesPage::update_controls ()
+{
+  bool has_error = false;
+
+  value_le->setText (QString ());
+  value_le->setEnabled (false);
+
+  colors->setEnabled (false_color_control->has_selection ());
+  colors->set_single_mode (false);
+
+  if (false_color_control->has_selection () && false_color_control->selected_node () > 0 && false_color_control->selected_node () < int (false_color_control->nodes ().size ()) - 1) {
+
+    double xmin, xmax;
+    get_xmin_xmax (xmin, xmax, has_error);
+
+    if (! has_error) {
+
+      double x = false_color_control->nodes () [false_color_control->selected_node ()].first;
+      double xx = x * (xmax - xmin) + xmin;
+
+      value_le->setText (tl::to_qstring (tl::sprintf ("%.4g", xx)));
+      value_le->setEnabled (true);
+
+    }
+
+  } else if (false_color_control->has_selection ()) {
+
+    colors->set_single_mode (true);
+
+  }
+
+  return has_error;
+}
+
 void
 PropertiesPage::color_mapping_changed ()
 {
-  if (! m_no_signals) {
-
-    bool has_error = false;
-
-    value_le->setText (QString ());
-    value_le->setEnabled (false);
-
-    colors->setEnabled (false_color_control->has_selection ());
-    colors->set_single_mode (false);
-
-    if (false_color_control->has_selection () && false_color_control->selected_node () > 0 && false_color_control->selected_node () < int (false_color_control->nodes ().size ()) - 1) {
-
-      double xmin, xmax;
-      get_xmin_xmax (xmin, xmax, has_error);
-
-      if (! has_error) {
-
-        double x = false_color_control->nodes () [false_color_control->selected_node ()].first;
-        double xx = x * (xmax - xmin) + xmin;
-
-        value_le->setText (tl::to_qstring (tl::sprintf ("%.4g", xx)));
-        value_le->setEnabled (true);
-
-      }
-
-    } else if (false_color_control->has_selection ()) {
-
-      colors->set_single_mode (true);
-
-    }
-
-    if (! has_error) {
-      m_in_color_mapping_signal = true;
-      emit edited ();
-      m_in_color_mapping_signal = false;
-    }
-
+  if (! m_no_signals && ! update_controls ()) {
+    m_in_color_mapping_signal = true;
+    emit edited ();
+    m_in_color_mapping_signal = false;
   }
 }
 
@@ -509,6 +511,7 @@ PropertiesPage::update ()
 
   m_no_signals = false;
 
+  update_controls ();
   recompute_histogram ();
 }
 
diff --git a/src/img/img/imgPropertiesPage.h b/src/img/img/imgPropertiesPage.h
index c799775b0..06d73b173 100644
--- a/src/img/img/imgPropertiesPage.h
+++ b/src/img/img/imgPropertiesPage.h
@@ -101,6 +101,7 @@ private:
   void invalidate ();
   void init ();
   void get_xmin_xmax (double &xmin, double &xmax, bool &has_error_out);
+  bool update_controls ();
 };
 
 }
diff --git a/src/lay/lay/layApplication.cc b/src/lay/lay/layApplication.cc
index 63b6450cf..259a272b0 100644
--- a/src/lay/lay/layApplication.cc
+++ b/src/lay/lay/layApplication.cc
@@ -1658,6 +1658,12 @@ GuiApplication::event (QEvent *event)
   return QApplication::event(event);
 }
 
+static void atexit_handler ()
+{
+  if (lay::ApplicationBase::instance ()) {
+    lay::ApplicationBase::instance ()->shutdown ();
+  }
+}
 
 int
 GuiApplication::exec ()
@@ -1693,6 +1699,10 @@ GuiApplication::exec ()
 
   }
 
+  //  register an exit handler to shutdown cleanly in case of an explicit exit
+  //  inside the code
+  ::atexit (&atexit_handler);
+
   return QApplication::exec ();
 }
 
diff --git a/src/lay/lay/layApplication.h b/src/lay/lay/layApplication.h
index e268df204..2a1322dfe 100644
--- a/src/lay/lay/layApplication.h
+++ b/src/lay/lay/layApplication.h
@@ -105,6 +105,15 @@ public:
    */
   void exit (int result);
 
+  /**
+   *  @brief Shut down the application
+   *
+   *  Calling this function will close the main window and
+   *  prepare for exit. Unlike "exit", it dows not actually exit
+   *  the process.
+   */
+  virtual void shutdown ();
+
   /**
    *  @brief Return the program's version
    */
@@ -330,7 +339,6 @@ public:
 
 protected:
   virtual void setup () = 0;
-  virtual void shutdown ();
   virtual void prepare_recording (const std::string &gtf_record, bool gtf_record_incremental);
   virtual void start_recording ();
   virtual lay::Dispatcher *dispatcher () const = 0;
diff --git a/src/lay/lay/layClipDialog.cc b/src/lay/lay/layClipDialog.cc
index a9dc2ae84..ca273cb56 100644
--- a/src/lay/lay/layClipDialog.cc
+++ b/src/lay/lay/layClipDialog.cc
@@ -168,12 +168,14 @@ BEGIN_PROTECTED
 
   } else if (rb_shapes->isChecked ()) {
 
+    lay::CellView ccv = view ()->cellview (cb_layer->cv_index ());
     int sel_layer = cb_layer->current_layer ();
-    if (sel_layer < 0 || ! cv->layout ().is_valid_layer (sel_layer)) {
+
+    if (! ccv.is_valid () || sel_layer < 0 || ! ccv->layout ().is_valid_layer (sel_layer)) {
       throw tl::Exception (tl::to_string (QObject::tr ("No valid layer selected to get clip boxes from")));
     }
 
-    db::collect_clip_boxes (cv->layout (), cv.cell_index (), (unsigned int) sel_layer, clip_boxes);
+    db::collect_clip_boxes (ccv->layout (), ccv.cell_index (), (unsigned int) sel_layer, clip_boxes);
 
   }
 
diff --git a/src/lay/lay/layMainWindow.cc b/src/lay/lay/layMainWindow.cc
index 13c76abcf..f63026e95 100644
--- a/src/lay/lay/layMainWindow.cc
+++ b/src/lay/lay/layMainWindow.cc
@@ -165,7 +165,6 @@ show_dock_widget (QDockWidget *dock_widget, bool visible)
 
 MainWindow::MainWindow (QApplication *app, const char *name, bool undo_enabled)
     : QMainWindow (0),
-      tl::Object (),
       lay::DispatcherDelegate (),
       m_dispatcher (this),
       m_text_progress (this, 10 /*verbosity threshold*/),
diff --git a/src/lay/lay/layMainWindow.h b/src/lay/lay/layMainWindow.h
index e1fc24972..a22ac7bc9 100644
--- a/src/lay/lay/layMainWindow.h
+++ b/src/lay/lay/layMainWindow.h
@@ -94,7 +94,6 @@ class ProgressWidget;
  */
 class LAY_PUBLIC MainWindow
   : public QMainWindow,
-    public tl::Object,
     public gsi::ObjectBase,
     public lay::DispatcherDelegate
 {
diff --git a/src/laybasic/laybasic/layDispatcher.h b/src/laybasic/laybasic/layDispatcher.h
index f42b60585..df26686d8 100644
--- a/src/laybasic/laybasic/layDispatcher.h
+++ b/src/laybasic/laybasic/layDispatcher.h
@@ -49,6 +49,7 @@ class ConfigureAction;
  *  @brief A delegate by which the dispatcher can submit notification events
  */
 class LAYBASIC_PUBLIC DispatcherDelegate
+  : public tl::Object
 {
 public:
   /**
@@ -271,7 +272,7 @@ private:
 #if defined(HAVE_QT)
   QWidget *mp_menu_parent_widget;
 #endif
-  DispatcherDelegate *mp_delegate;
+  tl::weak_ptr<DispatcherDelegate> mp_delegate;
 };
 
 }
diff --git a/src/laybasic/laybasic/layEditorOptionsPage.h b/src/laybasic/laybasic/layEditorOptionsPage.h
index c5d605bff..9e7deedd3 100644
--- a/src/laybasic/laybasic/layEditorOptionsPage.h
+++ b/src/laybasic/laybasic/layEditorOptionsPage.h
@@ -252,7 +252,7 @@ public:
   /**
    *  @brief Gets a value indicating whether the page is for that specific plugin (given by a declaration object)
    */
-  bool for_plugin_declaration (const lay::PluginDeclaration *pd)
+  bool for_plugin_declaration (const lay::PluginDeclaration *pd) const
   {
     return m_plugin_declarations.find (pd) != m_plugin_declarations.end ();
   }
diff --git a/src/laybasic/laybasic/layLayoutCanvas.cc b/src/laybasic/laybasic/layLayoutCanvas.cc
index bfa1a1747..2d93485f0 100644
--- a/src/laybasic/laybasic/layLayoutCanvas.cc
+++ b/src/laybasic/laybasic/layLayoutCanvas.cc
@@ -947,8 +947,10 @@ LayoutCanvas::screenshot ()
 void
 LayoutCanvas::resize_event (unsigned int width, unsigned int height)
 {
-  unsigned int w = width * dpr () + 0.5, h = height * dpr () + 0.5;
-  unsigned int wl = width * m_oversampling * dpr () + 0.5, hl = height * m_oversampling * dpr () + 0.5;
+  unsigned int w = (unsigned int) ceil (width * dpr () - db::epsilon);
+  unsigned int h = (unsigned int) ceil (height * dpr () - db::epsilon);
+  unsigned int wl = w * m_oversampling;
+  unsigned int hl = h * m_oversampling;
 
   if (m_viewport.width () != w || m_viewport.height () != h ||
       m_viewport_l.width () != wl || m_viewport_l.height () != hl) {
@@ -957,8 +959,8 @@ LayoutCanvas::resize_event (unsigned int width, unsigned int height)
     m_image_cache.clear ();
 
     //  set the viewport to the new size
-    m_viewport.set_size (width * dpr () + 0.5, height * dpr () + 0.5);
-    m_viewport_l.set_size (width * m_oversampling * dpr () + 0.5, height * m_oversampling * dpr () + 0.5);
+    m_viewport.set_size (w, h);
+    m_viewport_l.set_size (wl, hl);
 
     mouse_event_trans (db::DCplxTrans (1.0 / dpr ()) * m_viewport.trans ());
     do_redraw_all (true);
diff --git a/src/laybasic/laybasic/layLayoutViewBase.h b/src/laybasic/laybasic/layLayoutViewBase.h
index e754ebfbb..e3a1ff7b3 100644
--- a/src/laybasic/laybasic/layLayoutViewBase.h
+++ b/src/laybasic/laybasic/layLayoutViewBase.h
@@ -2225,6 +2225,14 @@ public:
     return pi;
   }
 
+  /**
+   *  @brief Gets the active plugin
+   */
+  lay::Plugin *active_plugin () const
+  {
+    return mp_active_plugin;
+  }
+
   /** 
    *  @brief Create a plugin of the given type
    *
@@ -3214,11 +3222,6 @@ protected:
 
   void init (db::Manager *mgr);
 
-  lay::Plugin *active_plugin () const
-  {
-    return mp_active_plugin;
-  }
-
   virtual LayoutView *get_ui ();
 
   bool configure (const std::string &name, const std::string &value);
diff --git a/src/laybasic/laybasic/layLayoutViewConfig.cc b/src/laybasic/laybasic/layLayoutViewConfig.cc
index f16fec969..2f68789bc 100644
--- a/src/laybasic/laybasic/layLayoutViewConfig.cc
+++ b/src/laybasic/laybasic/layLayoutViewConfig.cc
@@ -48,6 +48,12 @@ public:
     options.push_back (std::pair<std::string, std::string> (cfg_layers_always_show_ld, "true"));
     options.push_back (std::pair<std::string, std::string> (cfg_layers_always_show_layout_index, "false"));
     options.push_back (std::pair<std::string, std::string> (cfg_test_shapes_in_view, "false"));
+    options.push_back (std::pair<std::string, std::string> (cfg_layer_search_as_expressions, "true"));
+    options.push_back (std::pair<std::string, std::string> (cfg_layer_search_as_filter, "false"));
+    options.push_back (std::pair<std::string, std::string> (cfg_layer_search_case_sensitive, "true"));
+    options.push_back (std::pair<std::string, std::string> (cfg_cell_search_as_expressions, "true"));
+    options.push_back (std::pair<std::string, std::string> (cfg_cell_search_as_filter, "false"));
+    options.push_back (std::pair<std::string, std::string> (cfg_cell_search_case_sensitive, "true"));
     options.push_back (std::pair<std::string, std::string> (cfg_flat_cell_list, "false"));
     options.push_back (std::pair<std::string, std::string> (cfg_split_cell_list, "false"));
     options.push_back (std::pair<std::string, std::string> (cfg_cell_list_sorting, "by-name"));
diff --git a/src/laybasic/laybasic/layMove.cc b/src/laybasic/laybasic/layMove.cc
index b23f7c3bc..b270ab585 100644
--- a/src/laybasic/laybasic/layMove.cc
+++ b/src/laybasic/laybasic/layMove.cc
@@ -437,9 +437,12 @@ MoveService::drag_cancel ()
 {
   m_shift = db::DPoint ();
   if (m_dragging) {
+
     show_toolbox (false);
     ui ()->ungrab_mouse (this);
+
     m_dragging = false;
+
   }
 }
 
diff --git a/src/laybasic/laybasic/laySelector.cc b/src/laybasic/laybasic/laySelector.cc
index 9d60b1e63..241b9f496 100644
--- a/src/laybasic/laybasic/laySelector.cc
+++ b/src/laybasic/laybasic/laySelector.cc
@@ -332,6 +332,14 @@ public:
   {
     return new SelectionService (view);
   }
+
+  virtual std::vector<std::string> additional_editor_options_pages () const
+  {
+    std::vector<std::string> names;
+    //  TODO: provide in a central place instead of borrowing from the edt module
+    names.push_back ("GenericEditorOptions");
+    return names;
+  }
 };
 
 static tl::RegisteredClass<lay::PluginDeclaration> selection_service_decl (new SelectionServiceDeclaration (), -980, "laybasic::SelectionServicePlugin");
diff --git a/src/laybasic/laybasic/laybasicConfig.h b/src/laybasic/laybasic/laybasicConfig.h
index 78dc40fbf..11194126b 100644
--- a/src/laybasic/laybasic/laybasicConfig.h
+++ b/src/laybasic/laybasic/laybasicConfig.h
@@ -135,6 +135,13 @@ static const std::string cfg_layers_always_show_layout_index ("layers-always-sho
 static const std::string cfg_reader_options_show_always ("reader-options-show-always");
 static const std::string cfg_tip_window_hidden ("tip-window-hidden");
 
+static const std::string cfg_layer_search_as_expressions ("layer-search-as-expressions");
+static const std::string cfg_layer_search_as_filter ("layer-search-as-filter");
+static const std::string cfg_layer_search_case_sensitive ("layer-search-case-sensitive");
+static const std::string cfg_cell_search_as_expressions ("cell-search-as-expressions");
+static const std::string cfg_cell_search_as_filter ("cell-search-as-filter");
+static const std::string cfg_cell_search_case_sensitive ("cell-search-case-sensitive");
+
 static const std::string cfg_bitmap_oversampling ("bitmap-oversampling");
 static const std::string cfg_highres_mode ("highres-mode");
 static const std::string cfg_subres_mode ("subres-mode");
diff --git a/src/layui/layui/layHierarchyControlPanel.cc b/src/layui/layui/layHierarchyControlPanel.cc
index 2b948058c..4a7d9a6ef 100644
--- a/src/layui/layui/layHierarchyControlPanel.cc
+++ b/src/layui/layui/layHierarchyControlPanel.cc
@@ -264,7 +264,7 @@ HierarchyControlPanel::HierarchyControlPanel (lay::LayoutViewBase *view, QWidget
   mp_search_edit_box->set_escape_signal_enabled (true);
   mp_search_edit_box->set_tab_signal_enabled (true);
   connect (mp_search_edit_box, SIGNAL (returnPressed ()), this, SLOT (search_editing_finished ()));
-  connect (mp_search_edit_box, SIGNAL (textEdited (const QString &)), this, SLOT (search_edited ()));
+  connect (mp_search_edit_box, SIGNAL (textEdited (const QString &)), this, SLOT (search_edited_no_signal ()));
   connect (mp_search_edit_box, SIGNAL (esc_pressed ()), this, SLOT (search_editing_finished ()));
   connect (mp_search_edit_box, SIGNAL (tab_pressed ()), this, SLOT (search_next ()));
   connect (mp_search_edit_box, SIGNAL (backtab_pressed ()), this, SLOT (search_prev ()));
@@ -452,8 +452,42 @@ HierarchyControlPanel::search_triggered (const QString &t)
   }
 }
 
+void
+HierarchyControlPanel::set_search_as_filter (bool f)
+{
+  if (f != search_as_filter ()) {
+    mp_filter->setChecked (f);
+    search_edited_no_signal ();
+  }
+}
+
+void
+HierarchyControlPanel::set_search_case_sensitive (bool f)
+{
+  if (f != search_case_sensitive ()) {
+    mp_case_sensitive->setChecked (f);
+    search_edited_no_signal ();
+  }
+}
+
+void
+HierarchyControlPanel::set_search_as_expression (bool f)
+{
+  if (f != search_as_expression ()) {
+    mp_use_regular_expressions->setChecked (f);
+    search_edited_no_signal ();
+  }
+}
+
 void
 HierarchyControlPanel::search_edited ()
+{
+  search_edited_no_signal ();
+  emit search_options_changed ();
+}
+
+void
+HierarchyControlPanel::search_edited_no_signal ()
 {
   bool filter_invalid = false;
 
diff --git a/src/layui/layui/layHierarchyControlPanel.h b/src/layui/layui/layHierarchyControlPanel.h
index f363d77a1..e7b6bf044 100644
--- a/src/layui/layui/layHierarchyControlPanel.h
+++ b/src/layui/layui/layHierarchyControlPanel.h
@@ -152,6 +152,52 @@ public:
     return m_active_index;
   }
 
+
+  /**
+   *  @brief Sets the "as_filter" flag for the search feature
+   *
+   *  If this flag is set, search expressions are applied as filter
+   */
+  void set_search_as_filter (bool f);
+
+  /**
+   *  @brief Gets the "search_as_filter" flag
+   */
+  bool search_as_filter ()
+  {
+    return mp_filter->isChecked ();
+  }
+
+  /**
+   *  @brief Sets the "case_sensitive" flag for the search feature
+   *
+   *  If this flag is set, search expressions are case sensitive
+   */
+  void set_search_case_sensitive (bool f);
+
+  /**
+   *  @brief Gets the "case_sensitive" flag for the search feature
+   */
+  bool search_case_sensitive ()
+  {
+    return mp_case_sensitive->isChecked ();
+  }
+
+  /**
+   *  @brief Sets the "as_expression" flag for the search feature
+   *
+   *  If this flag is set, search expressions are handled as glob expressions
+   */
+  void set_search_as_expression (bool f);
+
+  /**
+   *  @brief Gets the "as_expression" flag for the search feature
+   */
+  bool search_as_expression ()
+  {
+    return mp_use_regular_expressions->isChecked ();
+  }
+
   /**
    *  @brief Returns the paths of the selected cells
    */
@@ -273,6 +319,7 @@ public:
 signals:
   void cell_selected (cell_path_type path, int cellview_index); 
   void active_cellview_changed (int cellview_index);
+  void search_options_changed ();
 
 public slots:
   void clicked (const QModelIndex &index);
@@ -283,6 +330,7 @@ public slots:
   void context_menu (const QPoint &pt);  
   void search_triggered (const QString &t);
   void search_edited ();
+  void search_edited_no_signal ();
   void search_editing_finished ();
   void search_next ();
   void search_prev ();
diff --git a/src/layui/layui/layLayerControlPanel.cc b/src/layui/layui/layLayerControlPanel.cc
index b7a2ba70c..d6861df73 100644
--- a/src/layui/layui/layLayerControlPanel.cc
+++ b/src/layui/layui/layLayerControlPanel.cc
@@ -257,7 +257,7 @@ LayerControlPanel::LayerControlPanel (lay::LayoutViewBase *view, db::Manager *ma
   mp_search_edit_box->set_escape_signal_enabled (true);
   mp_search_edit_box->set_tab_signal_enabled (true);
   connect (mp_search_edit_box, SIGNAL (returnPressed ()), this, SLOT (search_editing_finished ()));
-  connect (mp_search_edit_box, SIGNAL (textEdited (const QString &)), this, SLOT (search_edited ()));
+  connect (mp_search_edit_box, SIGNAL (textEdited (const QString &)), this, SLOT (search_edited_no_signal ()));
   connect (mp_search_edit_box, SIGNAL (esc_pressed ()), this, SLOT (search_editing_finished ()));
   connect (mp_search_edit_box, SIGNAL (tab_pressed ()), this, SLOT (search_next ()));
   connect (mp_search_edit_box, SIGNAL (backtab_pressed ()), this, SLOT (search_prev ()));
@@ -1160,12 +1160,46 @@ LayerControlPanel::search_triggered (const QString &t)
     mp_search_frame->show ();
     mp_search_edit_box->setText (t);
     mp_search_edit_box->setFocus ();
-    search_edited ();
+    search_edited_no_signal ();
+  }
+}
+
+void
+LayerControlPanel::set_search_as_filter (bool f)
+{
+  if (f != search_as_filter ()) {
+    mp_filter->setChecked (f);
+    search_edited_no_signal ();
+  }
+}
+
+void
+LayerControlPanel::set_search_case_sensitive (bool f)
+{
+  if (f != search_case_sensitive ()) {
+    mp_case_sensitive->setChecked (f);
+    search_edited_no_signal ();
+  }
+}
+
+void
+LayerControlPanel::set_search_as_expression (bool f)
+{
+  if (f != search_as_expression ()) {
+    mp_use_regular_expressions->setChecked (f);
+    search_edited_no_signal ();
   }
 }
 
 void
 LayerControlPanel::search_edited ()
+{
+  search_edited_no_signal ();
+  emit search_options_changed ();
+}
+
+void
+LayerControlPanel::search_edited_no_signal ()
 {
   if (! mp_model) {
     return;
diff --git a/src/layui/layui/layLayerControlPanel.h b/src/layui/layui/layLayerControlPanel.h
index fe2f6d920..32e6c0cd6 100644
--- a/src/layui/layui/layLayerControlPanel.h
+++ b/src/layui/layui/layLayerControlPanel.h
@@ -215,6 +215,51 @@ public:
     return mp_model->get_test_shapes_in_view ();
   }
 
+  /**
+   *  @brief Sets the "as_filter" flag for the search feature
+   *
+   *  If this flag is set, search expressions are applied as filter
+   */
+  void set_search_as_filter (bool f);
+
+  /**
+   *  @brief Gets the "search_as_filter" flag
+   */
+  bool search_as_filter ()
+  {
+    return mp_filter->isChecked ();
+  }
+
+  /**
+   *  @brief Sets the "case_sensitive" flag for the search feature
+   *
+   *  If this flag is set, search expressions are case sensitive
+   */
+  void set_search_case_sensitive (bool f);
+
+  /**
+   *  @brief Gets the "case_sensitive" flag for the search feature
+   */
+  bool search_case_sensitive ()
+  {
+    return mp_case_sensitive->isChecked ();
+  }
+
+  /**
+   *  @brief Sets the "as_expression" flag for the search feature
+   *
+   *  If this flag is set, search expressions are handled as glob expressions
+   */
+  void set_search_as_expression (bool f);
+
+  /**
+   *  @brief Gets the "as_expression" flag for the search feature
+   */
+  bool search_as_expression ()
+  {
+    return mp_use_regular_expressions->isChecked ();
+  }
+
   /**
    *  @brief Set the animation phase
    */
@@ -297,6 +342,7 @@ signals:
   void tab_changed ();
   void current_layer_changed (const lay::LayerPropertiesConstIterator &iter);
   void selected_layers_changed ();
+  void search_options_changed ();
 
 public slots:
   void cm_new_tab ();
@@ -344,6 +390,7 @@ public slots:
   void downdown_clicked ();
   void search_triggered (const QString &t);
   void search_edited ();
+  void search_edited_no_signal ();
   void search_editing_finished ();
   void search_next ();
   void search_prev ();
diff --git a/src/layui/layui/layWidgets.cc b/src/layui/layui/layWidgets.cc
index fc18882b1..93d61ec15 100644
--- a/src/layui/layui/layWidgets.cc
+++ b/src/layui/layui/layWidgets.cc
@@ -848,6 +848,12 @@ LayerSelectionComboBox::is_no_layer_selected () const
   return currentIndex () < 0;
 }
 
+int
+LayerSelectionComboBox::cv_index () const
+{
+  return mp_private->cv_index;
+}
+
 int 
 LayerSelectionComboBox::current_layer () const
 {
diff --git a/src/layui/layui/layWidgets.h b/src/layui/layui/layWidgets.h
index e812f2fbf..5a1eac17e 100644
--- a/src/layui/layui/layWidgets.h
+++ b/src/layui/layui/layWidgets.h
@@ -307,6 +307,14 @@ public:
    */
   bool is_no_layer_selected () const;
 
+  /**
+   *  @brief Gets the cellview index
+   *
+   *  NOTE: this methods returns -1 if the widget is not
+   *  associated with a cellview index.
+   */
+  int cv_index () const;
+
   /**
    *  @brief Get the current layer (index)
    *
diff --git a/src/layview/layview/layEditorOptionsPages.cc b/src/layview/layview/layEditorOptionsPages.cc
index 0db1877de..6e3dd2d6a 100644
--- a/src/layview/layview/layEditorOptionsPages.cc
+++ b/src/layview/layview/layEditorOptionsPages.cc
@@ -120,8 +120,13 @@ EditorOptionsPages::editor_options_pages ()
 bool
 EditorOptionsPages::has_content () const
 {
+  lay::Plugin *plugin = mp_view->active_plugin ();
+  if (! plugin) {
+    return false;
+  }
+
   for (auto p = m_pages.begin (); p != m_pages.end (); ++p) {
-    if (p->active () && ! p->is_modal_page () && ! p->is_toolbox_widget ()) {
+    if (! p->is_modal_page () && ! p->is_toolbox_widget () && p->for_plugin_declaration (plugin->plugin_declaration ())) {
       return true;
     }
   }
@@ -131,8 +136,13 @@ EditorOptionsPages::has_content () const
 bool
 EditorOptionsPages::has_modal_content () const
 {
+  lay::Plugin *plugin = mp_view->active_plugin ();
+  if (! plugin) {
+    return false;
+  }
+
   for (auto p = m_pages.begin (); p != m_pages.end (); ++p) {
-    if (p->active () && p->is_modal_page () && ! p->is_toolbox_widget ()) {
+    if (p->is_modal_page () && ! p->is_toolbox_widget () && p->for_plugin_declaration (plugin->plugin_declaration ())) {
       return true;
     }
   }
@@ -173,7 +183,7 @@ EditorOptionsPages::activate (const lay::Plugin *plugin)
     bool is_active = plugin && op->for_plugin_declaration (plugin->plugin_declaration ());
 
     //  The zero order page is picked as the initial one
-    if (is_active && ! op->active () && op->order () == 0 && page == 0) {
+    if (is_active && ! op->active () && (op->order () == 0 || page == 0)) {
       page = op.operator-> ();
     }
 
diff --git a/src/layview/layview/layLayoutView_qt.cc b/src/layview/layview/layLayoutView_qt.cc
index 3045f4881..6e51d4b28 100644
--- a/src/layview/layview/layLayoutView_qt.cc
+++ b/src/layview/layview/layLayoutView_qt.cc
@@ -404,6 +404,16 @@ void LayoutViewSignalConnector::layer_order_changed ()
   mp_view->layer_order_changed ();
 }
 
+void LayoutViewSignalConnector::layer_search_options_edited ()
+{
+  mp_view->layer_search_options_edited ();
+}
+
+void LayoutViewSignalConnector::cell_search_options_edited ()
+{
+  mp_view->cell_search_options_edited ();
+}
+
 void LayoutViewSignalConnector::min_hier_changed (int i)
 {
   mp_view->min_hier_changed (i);
@@ -573,6 +583,7 @@ LayoutView::init_ui (db::Manager *mgr)
       mp_hierarchy_panel = new lay::HierarchyControlPanel (this, hierarchy_frame, "hcp");
       left_frame_ly->addWidget (mp_hierarchy_panel, 1 /*stretch*/);
 
+      QObject::connect (mp_hierarchy_panel, SIGNAL (search_options_changed ()), mp_connector, SLOT (cell_search_options_edited ()));
       QObject::connect (mp_hierarchy_panel, SIGNAL (cell_selected (cell_path_type, int)), mp_connector, SLOT (select_cell_dispatch (cell_path_type, int)));
       QObject::connect (mp_hierarchy_panel, SIGNAL (active_cellview_changed (int)), mp_connector, SLOT (active_cellview_changed (int)));
       QObject::connect (mp_hierarchy_frame, SIGNAL (destroyed ()), mp_connector, SLOT (side_panel_destroyed ()));
@@ -655,6 +666,7 @@ LayoutView::init_ui (db::Manager *mgr)
       mp_control_frame = mp_control_panel;
 
       QObject::connect (mp_control_frame, SIGNAL (destroyed ()), mp_connector, SLOT (side_panel_destroyed ()));
+      QObject::connect (mp_control_frame, SIGNAL (search_options_changed ()), mp_connector, SLOT (layer_search_options_edited ()));
       QObject::connect (mp_control_panel, SIGNAL (tab_changed ()), mp_connector, SLOT (layer_tab_changed ()));
       QObject::connect (mp_control_panel, SIGNAL (order_changed ()), mp_connector, SLOT (layer_order_changed ()));
       QObject::connect (mp_control_panel, SIGNAL (current_layer_changed (const lay::LayerPropertiesConstIterator &)), mp_connector, SLOT (current_layer_changed_slot (const lay::LayerPropertiesConstIterator &)));
@@ -1041,6 +1053,60 @@ LayoutView::configure (const std::string &name, const std::string &value)
     }
     return true;
 
+  } else if (name == cfg_layer_search_as_expressions) {
+
+    bool f;
+    tl::from_string (value, f);
+    if (mp_control_panel) {
+      mp_control_panel->set_search_as_expression (f);
+    }
+    return true;
+
+  } else if (name == cfg_layer_search_as_filter) {
+
+    bool f;
+    tl::from_string (value, f);
+    if (mp_control_panel) {
+      mp_control_panel->set_search_as_filter (f);
+    }
+    return true;
+
+  } else if (name == cfg_layer_search_case_sensitive) {
+
+    bool f;
+    tl::from_string (value, f);
+    if (mp_control_panel) {
+      mp_control_panel->set_search_case_sensitive (f);
+    }
+    return true;
+
+  } else if (name == cfg_cell_search_as_expressions) {
+
+    bool f;
+    tl::from_string (value, f);
+    if (mp_hierarchy_panel) {
+      mp_hierarchy_panel->set_search_as_expression (f);
+    }
+    return true;
+
+  } else if (name == cfg_cell_search_as_filter) {
+
+    bool f;
+    tl::from_string (value, f);
+    if (mp_hierarchy_panel) {
+      mp_hierarchy_panel->set_search_as_filter (f);
+    }
+    return true;
+
+  } else if (name == cfg_cell_search_case_sensitive) {
+
+    bool f;
+    tl::from_string (value, f);
+    if (mp_hierarchy_panel) {
+      mp_hierarchy_panel->set_search_case_sensitive (f);
+    }
+    return true;
+
   } else if (name == cfg_layers_always_show_source) {
 
     bool a = false;
@@ -1299,6 +1365,26 @@ LayoutView::max_hier_changed (int i)
   set_hier_levels (std::make_pair (get_hier_levels ().first, i));
 }
 
+void
+LayoutView::layer_search_options_edited ()
+{
+  if (mp_control_panel) {
+    dispatcher ()->config_set (cfg_layer_search_as_expressions, mp_control_panel->search_as_expression ());
+    dispatcher ()->config_set (cfg_layer_search_case_sensitive, mp_control_panel->search_case_sensitive ());
+    dispatcher ()->config_set (cfg_layer_search_as_filter, mp_control_panel->search_as_filter ());
+  }
+}
+
+void
+LayoutView::cell_search_options_edited ()
+{
+  if (mp_hierarchy_panel) {
+    dispatcher ()->config_set (cfg_cell_search_as_expressions, mp_hierarchy_panel->search_as_expression ());
+    dispatcher ()->config_set (cfg_cell_search_case_sensitive, mp_hierarchy_panel->search_case_sensitive ());
+    dispatcher ()->config_set (cfg_cell_search_as_filter, mp_hierarchy_panel->search_as_filter ());
+  }
+}
+
 tl::Color
 LayoutView::default_background_color ()
 {
diff --git a/src/layview/layview/layLayoutView_qt.h b/src/layview/layview/layLayoutView_qt.h
index 5b9df8062..b7387aec3 100644
--- a/src/layview/layview/layLayoutView_qt.h
+++ b/src/layview/layview/layLayoutView_qt.h
@@ -114,6 +114,8 @@ public slots:
   void layer_tab_changed ();
   void layer_order_changed ();
   void select_cell_dispatch (const cell_path_type &path, int cellview_index);
+  void layer_search_options_edited ();
+  void cell_search_options_edited ();
   void min_hier_changed (int i);
   void max_hier_changed (int i);
   void app_terminated ();
@@ -654,6 +656,8 @@ private:
   void layer_order_changed ();
   void min_hier_changed (int i);
   void max_hier_changed (int i);
+  void layer_search_options_edited ();
+  void cell_search_options_edited ();
 
   bool event_filter (QObject *obj, QEvent *ev, bool &taken);
   QSize size_hint () const;
diff --git a/src/lvs/unit_tests/lvsSimpleTests.cc b/src/lvs/unit_tests/lvsSimpleTests.cc
index 53222d344..e248cee48 100644
--- a/src/lvs/unit_tests/lvsSimpleTests.cc
+++ b/src/lvs/unit_tests/lvsSimpleTests.cc
@@ -362,3 +362,9 @@ TEST(63_FlagMissingPorts)
   run_test (_this, "flag_missing_ports", "flag_missing_ports.gds", false, true, "TOP");
 }
 
+//  Split substrate - marker and global connection (issue #2345)
+TEST(64_SplitSubstrate)
+{
+  run_test (_this, "split_substrate", "split_substrate.gds", true, false /*no LVS*/);
+}
+
diff --git a/src/plugins/tools/density_map/density_map.pro b/src/plugins/tools/density_map/density_map.pro
new file mode 100644
index 000000000..f1dd4434b
--- /dev/null
+++ b/src/plugins/tools/density_map/density_map.pro
@@ -0,0 +1,6 @@
+
+TEMPLATE = subdirs
+
+!equals(HAVE_QT, "0") {
+  SUBDIRS = lay_plugin
+}
diff --git a/src/plugins/tools/density_map/lay_plugin/DensityMapDialog.ui b/src/plugins/tools/density_map/lay_plugin/DensityMapDialog.ui
new file mode 100644
index 000000000..ded9b81ce
--- /dev/null
+++ b/src/plugins/tools/density_map/lay_plugin/DensityMapDialog.ui
@@ -0,0 +1,600 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>DensityMapDialog</class>
+ <widget class="QDialog" name="DensityMapDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>657</width>
+    <height>480</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Density Map</string>
+  </property>
+  <layout class="QVBoxLayout">
+   <property name="spacing">
+    <number>6</number>
+   </property>
+   <property name="margin" stdset="0">
+    <number>9</number>
+   </property>
+   <item>
+    <widget class="QFrame" name="frame_3">
+     <property name="frameShape">
+      <enum>QFrame::NoFrame</enum>
+     </property>
+     <property name="frameShadow">
+      <enum>QFrame::Raised</enum>
+     </property>
+     <layout class="QHBoxLayout">
+      <property name="spacing">
+       <number>6</number>
+      </property>
+      <property name="margin" stdset="0">
+       <number>0</number>
+      </property>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_3">
+     <property name="title">
+      <string>Density map parameters</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout_2">
+      <item row="0" column="1">
+       <widget class="QLineEdit" name="le_pixel_size">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="text">
+         <string>100</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="0">
+       <widget class="QLabel" name="label_7">
+        <property name="text">
+         <string>Pixel size</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QLineEdit" name="le_window_size">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="2">
+       <widget class="QLabel" name="label_8">
+        <property name="text">
+         <string>µm</string>
+        </property>
+       </widget>
+      </item>
+      <item row="3" column="1">
+       <widget class="QSpinBox" name="sb_threads">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="minimum">
+         <number>1</number>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="label_11">
+        <property name="text">
+         <string>Averaging window size</string>
+        </property>
+       </widget>
+      </item>
+      <item row="3" column="0">
+       <widget class="QLabel" name="label_9">
+        <property name="text">
+         <string>Threads</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="3">
+       <spacer name="horizontalSpacer_2">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>353</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+      <item row="1" column="2" colspan="2">
+       <widget class="QLabel" name="label_10">
+        <property name="text">
+         <string>µm (a multiple of the pixel size or empty)</string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="0">
+       <widget class="QLabel" name="label_12">
+        <property name="text">
+         <string>Boundary mode</string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="1" colspan="3">
+       <widget class="QComboBox" name="cb_boundary_mode">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="sizeAdjustPolicy">
+         <enum>QComboBox::AdjustToContents</enum>
+        </property>
+        <item>
+         <property name="text">
+          <string>Periodic (repeat region seamlessly)</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Use zero density outside</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Use 100% density outside</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Use average density outside</string>
+         </property>
+        </item>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox_2">
+     <property name="title">
+      <string>Compute density of shapes on</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout">
+      <item row="0" column="2" colspan="2">
+       <widget class="QStackedWidget" name="layer_stack">
+        <property name="currentIndex">
+         <number>1</number>
+        </property>
+        <widget class="QWidget" name="page_3">
+         <layout class="QHBoxLayout" name="horizontalLayout_4">
+          <property name="leftMargin">
+           <number>0</number>
+          </property>
+          <property name="topMargin">
+           <number>0</number>
+          </property>
+          <property name="rightMargin">
+           <number>0</number>
+          </property>
+          <property name="bottomMargin">
+           <number>0</number>
+          </property>
+          <item>
+           <widget class="lay::LayerSelectionComboBox" name="cb_source_layer">
+            <property name="enabled">
+             <bool>true</bool>
+            </property>
+            <property name="sizeAdjustPolicy">
+             <enum>QComboBox::AdjustToContents</enum>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <spacer name="horizontalSpacer">
+            <property name="orientation">
+             <enum>Qt::Horizontal</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>385</width>
+              <height>20</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+         </layout>
+        </widget>
+        <widget class="QWidget" name="page_4">
+         <layout class="QHBoxLayout" name="horizontalLayout_3"/>
+        </widget>
+       </widget>
+      </item>
+      <item row="0" column="0">
+       <widget class="QComboBox" name="layer_cb">
+        <item>
+         <property name="text">
+          <string>Layer</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Visible layers</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Selected layers</string>
+         </property>
+        </item>
+       </widget>
+      </item>
+      <item row="0" column="1">
+       <spacer name="horizontalSpacer_4">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeType">
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>8</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="groupBox">
+     <property name="title">
+      <string>Compute density map of region</string>
+     </property>
+     <layout class="QGridLayout">
+      <property name="spacing">
+       <number>6</number>
+      </property>
+      <item row="1" column="0">
+       <widget class="QFrame" name="frame_2">
+        <property name="frameShape">
+         <enum>QFrame::NoFrame</enum>
+        </property>
+        <property name="frameShadow">
+         <enum>QFrame::Raised</enum>
+        </property>
+        <layout class="QVBoxLayout">
+         <property name="spacing">
+          <number>6</number>
+         </property>
+         <property name="margin" stdset="0">
+          <number>0</number>
+         </property>
+         <item>
+          <spacer>
+           <property name="orientation">
+            <enum>Qt::Vertical</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>20</width>
+             <height>40</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
+       </widget>
+      </item>
+      <item row="2" column="0">
+       <widget class="QFrame" name="frame">
+        <property name="frameShape">
+         <enum>QFrame::NoFrame</enum>
+        </property>
+        <property name="frameShadow">
+         <enum>QFrame::Raised</enum>
+        </property>
+        <layout class="QVBoxLayout">
+         <property name="spacing">
+          <number>6</number>
+         </property>
+         <property name="margin" stdset="0">
+          <number>0</number>
+         </property>
+        </layout>
+       </widget>
+      </item>
+      <item row="0" column="2" rowspan="2" colspan="2">
+       <widget class="QStackedWidget" name="region_stack">
+        <property name="currentIndex">
+         <number>2</number>
+        </property>
+        <widget class="QWidget" name="page">
+         <layout class="QGridLayout" name="gridLayout_3">
+          <property name="leftMargin">
+           <number>0</number>
+          </property>
+          <property name="topMargin">
+           <number>0</number>
+          </property>
+          <property name="rightMargin">
+           <number>0</number>
+          </property>
+          <property name="bottomMargin">
+           <number>0</number>
+          </property>
+          <item row="0" column="0">
+           <widget class="lay::LayerSelectionComboBox" name="cb_box_layer">
+            <property name="enabled">
+             <bool>true</bool>
+            </property>
+            <property name="sizeAdjustPolicy">
+             <enum>QComboBox::AdjustToContents</enum>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1">
+           <spacer>
+            <property name="orientation">
+             <enum>Qt::Horizontal</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>351</width>
+              <height>20</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+          <item row="1" column="0">
+           <spacer name="verticalSpacer">
+            <property name="orientation">
+             <enum>Qt::Vertical</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>20</width>
+              <height>40</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+         </layout>
+        </widget>
+        <widget class="QWidget" name="page_2">
+         <layout class="QHBoxLayout" name="horizontalLayout_2">
+          <property name="leftMargin">
+           <number>0</number>
+          </property>
+          <property name="topMargin">
+           <number>0</number>
+          </property>
+          <property name="rightMargin">
+           <number>0</number>
+          </property>
+          <property name="bottomMargin">
+           <number>0</number>
+          </property>
+          <item>
+           <widget class="QGroupBox" name="region_box_group">
+            <property name="enabled">
+             <bool>true</bool>
+            </property>
+            <property name="title">
+             <string>Box Boundaries (all values in µm)</string>
+            </property>
+            <layout class="QGridLayout" name="_2">
+             <property name="margin" stdset="0">
+              <number>9</number>
+             </property>
+             <property name="spacing">
+              <number>6</number>
+             </property>
+             <item row="1" column="3">
+              <widget class="QLabel" name="label_6">
+               <property name="text">
+                <string>y =</string>
+               </property>
+              </widget>
+             </item>
+             <item row="1" column="0">
+              <widget class="QLabel" name="label_5">
+               <property name="text">
+                <string>2nd corner</string>
+               </property>
+              </widget>
+             </item>
+             <item row="1" column="1">
+              <widget class="QLabel" name="label_4">
+               <property name="text">
+                <string>x =</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="0">
+              <widget class="QLabel" name="label_3">
+               <property name="text">
+                <string>1st corner</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="1">
+              <widget class="QLabel" name="label">
+               <property name="text">
+                <string>x =</string>
+               </property>
+              </widget>
+             </item>
+             <item row="0" column="3">
+              <widget class="QLabel" name="label_2">
+               <property name="text">
+                <string>y =</string>
+               </property>
+              </widget>
+             </item>
+             <item row="1" column="4">
+              <widget class="QLineEdit" name="le_y2"/>
+             </item>
+             <item row="1" column="2">
+              <widget class="QLineEdit" name="le_x2"/>
+             </item>
+             <item row="0" column="4">
+              <widget class="QLineEdit" name="le_y1"/>
+             </item>
+             <item row="0" column="2">
+              <widget class="QLineEdit" name="le_x1"/>
+             </item>
+            </layout>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+        <widget class="QWidget" name="page_5"/>
+       </widget>
+      </item>
+      <item row="0" column="0">
+       <widget class="QComboBox" name="region_cb">
+        <item>
+         <property name="text">
+          <string>Global bounding box</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Bounding box of layer ...</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Single box with ..</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Visible region</string>
+         </property>
+        </item>
+        <item>
+         <property name="text">
+          <string>Defined by rulers</string>
+         </property>
+        </item>
+       </widget>
+      </item>
+      <item row="0" column="1">
+       <spacer name="horizontalSpacer_3">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeType">
+         <enum>QSizePolicy::Fixed</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>8</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <spacer>
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>40</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="button_box">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Apply|QDialogButtonBox::Close|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>lay::LayerSelectionComboBox</class>
+   <extends>QComboBox</extends>
+   <header>layWidgets.h</header>
+  </customwidget>
+ </customwidgets>
+ <tabstops>
+  <tabstop>le_pixel_size</tabstop>
+  <tabstop>sb_threads</tabstop>
+  <tabstop>layer_cb</tabstop>
+  <tabstop>cb_source_layer</tabstop>
+  <tabstop>region_cb</tabstop>
+  <tabstop>cb_box_layer</tabstop>
+  <tabstop>le_x1</tabstop>
+  <tabstop>le_y1</tabstop>
+  <tabstop>le_x2</tabstop>
+  <tabstop>le_y2</tabstop>
+ </tabstops>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>button_box</sender>
+   <signal>accepted()</signal>
+   <receiver>DensityMapDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>button_box</sender>
+   <signal>rejected()</signal>
+   <receiver>DensityMapDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/src/plugins/tools/density_map/lay_plugin/layDensityMapDialog.cc b/src/plugins/tools/density_map/lay_plugin/layDensityMapDialog.cc
new file mode 100644
index 000000000..b6e280797
--- /dev/null
+++ b/src/plugins/tools/density_map/lay_plugin/layDensityMapDialog.cc
@@ -0,0 +1,765 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2026 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+
+#include "layDensityMapDialog.h"
+
+#include "dbClip.h"
+#include "dbTilingProcessor.h"
+#include "antService.h"
+#include "tlException.h"
+#include "tlString.h"
+#include "tlExceptions.h"
+#include "layUtils.h"
+#include "imgObject.h"
+#include "imgService.h"
+
+namespace lay
+{
+
+static const std::string layer_mode_specific ("layer-mode-specific");
+static const std::string layer_mode_visible ("layer-mode-visible");
+static const std::string layer_mode_selected ("layer-mode-selected");
+
+//  items in layer_cb
+static const std::vector<std::string> layer_modes = { layer_mode_specific, layer_mode_visible, layer_mode_selected };
+
+static const std::string region_mode_global_bbox ("region-mode-global-bbox");
+static const std::string region_mode_layer_bbox ("region-mode-layer-bbox");
+static const std::string region_mode_single_box ("region-mode-single-box");
+static const std::string region_mode_visible_region ("region-mode-visible-region");
+static const std::string region_mode_by_rulers ("region-mode-by-rulers");
+
+//  items in region_cb
+static const std::vector<std::string> region_modes = {
+  region_mode_global_bbox,
+  region_mode_layer_bbox,
+  region_mode_single_box,
+  region_mode_visible_region,
+  region_mode_by_rulers
+};
+
+static const std::string boundary_mode_periodic ("boundary-mode-periodic");
+static const std::string boundary_mode_zero ("boundary-mode-zero");
+static const std::string boundary_mode_one ("boundary-mode-one");
+static const std::string boundary_mode_average ("boundary-mode-average");
+
+//  items in boundary_mode_cb
+static const std::vector<std::string> boundary_modes = { boundary_mode_periodic, boundary_mode_zero, boundary_mode_one, boundary_mode_average };
+
+static const std::string cfg_density_map_region_mode ("density-map-region-mode");
+static const std::string cfg_density_map_layer_mode ("density-map-layer-mode");
+static const std::string cfg_density_map_pixel_size ("density-map-pixel-size");
+static const std::string cfg_density_map_window_size ("density-map-window-size");
+static const std::string cfg_density_map_boundary_mode ("density-map-boundary-mode");
+static const std::string cfg_density_map_threads ("density-map-threads");
+static const std::string cfg_density_map_source_layer ("density-map-source-layer");
+static const std::string cfg_density_map_box_layer ("density-map-box-layer");
+static const std::string cfg_density_map_single_box ("density-map-single-box");
+
+// ------------------------------------------------------------
+//  Declaration of the configuration options
+
+class DensityMapDialogPluginDeclaration
+  : public lay::PluginDeclaration
+{
+public:
+  virtual void get_options (std::vector < std::pair<std::string, std::string> > &options) const
+  {
+    options.push_back (std::make_pair (cfg_density_map_layer_mode, layer_mode_specific));
+    options.push_back (std::make_pair (cfg_density_map_region_mode, region_mode_global_bbox));
+    options.push_back (std::make_pair (cfg_density_map_pixel_size, "100"));
+    options.push_back (std::make_pair (cfg_density_map_window_size, "0"));
+    options.push_back (std::make_pair (cfg_density_map_boundary_mode, boundary_mode_periodic));
+    options.push_back (std::make_pair (cfg_density_map_threads, "1"));
+  }
+
+  virtual lay::ConfigPage *config_page (QWidget * /*parent*/, std::string & /*title*/) const
+  {
+    return 0; //  .. no config page yet ..
+  }
+
+  virtual void get_menu_entries (std::vector<lay::MenuEntry> &menu_entries) const
+  {
+    lay::PluginDeclaration::get_menu_entries (menu_entries);
+    menu_entries.push_back (lay::menu_item ("density_map::show", "density_map_tool:edit", "tools_menu.post_verification_group", tl::to_string (QObject::tr ("Density Map"))));
+  }
+ 
+  virtual lay::Plugin *create_plugin (db::Manager *, lay::Dispatcher *root, lay::LayoutViewBase *view) const
+  {
+    if (lay::has_gui ()) {
+      return new DensityMapDialog (root, view);
+    } else {
+      return 0;
+    }
+  }
+};
+
+static tl::RegisteredClass<lay::PluginDeclaration> config_decl (new DensityMapDialogPluginDeclaration (), 3002, "lay::DensityMapPlugin");
+
+
+// ------------------------------------------------------------
+
+DensityMapDialog::DensityMapDialog (lay::Dispatcher *root, LayoutViewBase *vw)
+  : lay::Browser (root, vw), 
+    Ui::DensityMapDialog ()
+{
+  Ui::DensityMapDialog::setupUi (this);
+
+  connect (layer_cb, SIGNAL (activated (int)), SLOT (layer_mode_changed (int)));
+  connect (region_cb, SIGNAL (activated (int)), SLOT (region_mode_changed (int)));
+
+  connect (button_box->button (QDialogButtonBox::Apply), SIGNAL (clicked ()), this, SLOT (apply ()));
+
+  region_mode_changed (region_cb->currentIndex ());
+  layer_mode_changed (layer_cb->currentIndex ());
+}
+
+void
+DensityMapDialog::region_mode_changed (int mode)
+{
+  if (mode < 0 || mode >= int (region_modes.size ())) {
+    return;
+  }
+
+  const auto &rm = region_modes [mode];
+  if (rm == region_mode_layer_bbox) {
+    region_stack->setCurrentIndex (0);
+  } else if (rm == region_mode_single_box) {
+    region_stack->setCurrentIndex (1);
+  } else {
+    region_stack->setCurrentIndex (2);
+  }
+}
+
+void
+DensityMapDialog::layer_mode_changed (int mode)
+{
+  if (mode < 0 || mode >= int (layer_modes.size ())) {
+    return;
+  }
+
+  const auto &lm = layer_modes [mode];
+  if (lm == layer_mode_specific) {
+    layer_stack->setCurrentIndex (0);
+  } else {
+    layer_stack->setCurrentIndex (1);
+  }
+}
+
+void 
+DensityMapDialog::menu_activated (const std::string &symbol)
+{
+  if (symbol == "density_map::show") {
+
+    int cv_index = view ()->active_cellview_index ();
+
+    lay::CellView cv = view ()->cellview (cv_index);
+    if (cv.is_valid ()) {
+      cb_box_layer->set_view (view (), cv_index);
+      cb_source_layer->set_view (view (), cv_index);
+      show ();
+      activate ();
+    }
+
+  } else {
+    lay::Browser::menu_activated (symbol);
+  }
+}
+
+DensityMapDialog::~DensityMapDialog ()
+{
+  //  .. nothing yet ..
+}
+
+namespace
+{
+
+  class DensityMapTileReceiver
+    : public db::TileOutputReceiver
+  {
+  public:
+    DensityMapTileReceiver (img::Object *img)
+      : mp_img (img)
+    {
+      //  .. nothing yet ..
+    }
+
+    virtual void put (size_t ix, size_t iy, const db::Box &tile, size_t /*id*/, const tl::Variant &obj, double /*dbu*/, const db::ICplxTrans & /*trans*/, bool /*clip*/)
+    {
+      if (tl::verbosity () >= 30) {
+        tl::info << "Density map value: " << ix << "," << iy << " " << tile.to_string () << " -> " << obj.to_string ();
+      }
+
+      mp_img->set_pixel (ix, iy, obj.to_double ());
+    }
+
+  private:
+    img::Object *mp_img;
+  };
+
+}
+
+void
+DensityMapDialog::apply ()
+{
+BEGIN_PROTECTED
+
+  make_density_map ();
+
+END_PROTECTED
+}
+
+void
+DensityMapDialog::accept ()
+{
+BEGIN_PROTECTED
+
+  make_density_map ();
+
+  //  close this dialog
+  QDialog::accept ();
+
+END_PROTECTED
+}
+
+bool
+DensityMapDialog::configure (const std::string &name, const std::string &value)
+{
+  if (name == cfg_density_map_layer_mode) {
+
+    int mode = 0;
+    for (size_t i = 0; i < layer_modes.size (); ++i) {
+      if (layer_modes[i] == value) {
+        mode = int (i);
+      }
+    }
+
+    layer_cb->setCurrentIndex (mode);
+    layer_mode_changed (mode);
+    return true;
+
+  } else if (name == cfg_density_map_region_mode) {
+
+    int mode = 0;
+    for (size_t i = 0; i < region_modes.size (); ++i) {
+      if (region_modes[i] == value) {
+        mode = int (i);
+      }
+    }
+
+    region_cb->setCurrentIndex (mode);
+    region_mode_changed (mode);
+    return true;
+
+  } else if (name == cfg_density_map_pixel_size) {
+
+    double px = 100.0;
+    try {
+      tl::from_string (value, px);
+      le_pixel_size->setText (tl::to_qstring (tl::to_string (px)));
+    } catch (...) {
+    }
+    return true;
+
+  } else if (name == cfg_density_map_window_size) {
+
+    double ws = 0.0;
+    try {
+      tl::from_string (value, ws);
+      if (ws > 0) {
+        le_window_size->setText (tl::to_qstring (tl::to_string (ws)));
+      } else {
+        le_window_size->setText (QString ());
+      }
+    } catch (...) {
+    }
+    return true;
+
+  } else if (name == cfg_density_map_boundary_mode) {
+
+    int mode = 0;
+    for (size_t i = 0; i < boundary_modes.size (); ++i) {
+      if (boundary_modes[i] == value) {
+        mode = int (i);
+      }
+    }
+
+    cb_boundary_mode->setCurrentIndex (mode);
+    return true;
+
+  } else if (name == cfg_density_map_threads) {
+
+    int thr = 1;
+    try {
+      tl::from_string (value, thr);
+      sb_threads->setValue (thr);
+    } catch (...) {
+    }
+    return true;
+
+  } else if (name == cfg_density_map_source_layer) {
+
+    db::LayerProperties lp;
+    try {
+      tl::from_string (value, lp);
+      cb_source_layer->set_current_layer (lp);
+    } catch (...) {
+    }
+    return true;
+
+  } else if (name == cfg_density_map_box_layer) {
+
+    db::LayerProperties lp;
+    try {
+      tl::from_string (value, lp);
+      cb_box_layer->set_current_layer (lp);
+    } catch (...) {
+    }
+    return true;
+
+  } else if (name == cfg_density_map_single_box) {
+
+    db::DBox bx;
+    try {
+      tl::from_string (value, bx);
+      if (bx.empty ()) {
+        le_x1->setText (QString ());
+        le_y1->setText (QString ());
+        le_x2->setText (QString ());
+        le_y2->setText (QString ());
+      } else {
+        le_x1->setText (tl::to_qstring (tl::to_string (bx.left ())));
+        le_y1->setText (tl::to_qstring (tl::to_string (bx.bottom ())));
+        le_x2->setText (tl::to_qstring (tl::to_string (bx.right ())));
+        le_y2->setText (tl::to_qstring (tl::to_string (bx.top ())));
+      }
+    } catch (...) {
+    }
+    return true;
+
+  } else {
+    return false;
+  }
+}
+
+void
+DensityMapDialog::make_density_map ()
+{
+  DensityMapParameters par;
+
+  par.threads = std::max (1, sb_threads->value ());
+
+  par.pixel_size = 0.0;
+  tl::from_string_ext (tl::to_string (le_pixel_size->text ()), par.pixel_size);
+
+  if (par.pixel_size < 1e-6) {
+    throw tl::Exception (tl::to_string (QObject::tr ("The pixel size must be positive and not zero")));
+  }
+
+  par.window_size = 0.0;
+  if (! le_window_size->text ().simplified ().isEmpty ()) {
+    tl::from_string_ext (tl::to_string (le_window_size->text ()), par.window_size);
+    if (par.window_size < 1e-6) {
+      throw tl::Exception (tl::to_string (QObject::tr ("The window size must be positive and not zero or empty")));
+    }
+  }
+
+  int boundary_mode = cb_boundary_mode->currentIndex ();
+  if (boundary_mode < 0 || boundary_mode >= int (boundary_modes.size ())) {
+    return;
+  }
+  par.boundary_mode = boundary_modes [boundary_mode];
+
+  int region_mode = region_cb->currentIndex ();
+  if (region_mode < 0 || region_mode >= int (region_modes.size ())) {
+    return;
+  }
+  const auto &rm = region_modes [region_mode];
+
+  int layer_mode = layer_cb->currentIndex ();
+  if (layer_mode < 0 || layer_mode >= int (layer_modes.size ())) {
+    return;
+  }
+  const auto &lm = layer_modes [layer_mode];
+
+  db::LayerProperties region_layer;
+  db::LayerProperties source_layer;
+
+  if (rm == region_mode_single_box) {
+
+    if (le_x1->text ().isEmpty () || le_x2->text ().isEmpty () ||
+        le_y1->text ().isEmpty () || le_y2->text ().isEmpty ()) {
+      throw tl::Exception (tl::to_string (QObject::tr ("All four coordinates of the clip box must be given")));
+    }
+
+    double x1 = 0.0, y1 = 0.0;
+    double x2 = 0.0, y2 = 0.0;
+    tl::from_string_ext (tl::to_string (le_x1->text ()), x1);
+    tl::from_string_ext (tl::to_string (le_x2->text ()), x2);
+    tl::from_string_ext (tl::to_string (le_y1->text ()), y1);
+    tl::from_string_ext (tl::to_string (le_y2->text ()), y2);
+
+    par.region = db::DBox (db::DPoint (x1, y1), db::DPoint (x2, y2));
+
+  } else if (rm == region_mode_by_rulers) {
+
+    ant::Service *ant_service = view ()->get_plugin <ant::Service> ();
+    if (ant_service) {
+      ant::AnnotationIterator ant = ant_service->begin_annotations ();
+      while (! ant.at_end ()) {
+        par.region += db::DBox (ant->p1 (), ant->p2 ());
+        ++ant;
+      }
+    }
+
+  } else if (rm == region_mode_layer_bbox) {
+
+    lay::CellView ccv = view ()->cellview (cb_box_layer->cv_index ());
+    int sel_layer = cb_box_layer->current_layer ();
+
+    region_layer = cb_box_layer->current_layer_props ();
+
+    if (! ccv.is_valid () || sel_layer < 0 || ! ccv->layout ().is_valid_layer (sel_layer)) {
+      throw tl::Exception (tl::to_string (QObject::tr ("No valid layer selected to get clip boxes from")));
+    }
+
+    par.region = db::CplxTrans (ccv->layout ().dbu ()) * ccv->layout ().cell (ccv.cell_index ()).bbox (sel_layer);
+
+  } else if (rm == region_mode_visible_region) {
+
+    par.region = view ()->box ();
+
+  } else {
+
+    lay::CellView cv = view ()->cellview (view ()->active_cellview_index ());
+    par.region = db::CplxTrans (cv->layout ().dbu ()) * cv->layout ().cell (cv.cell_index ()).bbox ();
+
+  }
+
+  if (lm == layer_mode_specific) {
+
+    int cvi = cb_source_layer->cv_index ();
+    lay::CellView ccv = view ()->cellview (cvi);
+    int sel_layer = cb_source_layer->current_layer ();
+
+    source_layer = cb_source_layer->current_layer_props ();
+
+    if (! ccv.is_valid () || sel_layer < 0 || ! ccv->layout ().is_valid_layer (sel_layer)) {
+      throw tl::Exception (tl::to_string (QObject::tr ("No valid layer selected to get clip boxes from")));
+    }
+
+    par.input_layers.push_back (std::make_pair (cvi, sel_layer));
+
+  } else if (lm == layer_mode_visible) {
+
+    for (auto l = view ()->begin_layers (); !l.at_end (); ++l) {
+
+      if (! l->has_children () && l->visible (true)) {
+
+        int cvi = (l->cellview_index () >= 0) ? l->cellview_index () : 0;
+        lay::CellView ccv = view ()->cellview (cvi);
+        int li = l->layer_index ();
+
+        if (ccv.is_valid () || li >= 0 || ! ccv->layout ().is_valid_layer (li)) {
+          par.input_layers.push_back (std::make_pair (cvi, li));
+        }
+
+      }
+
+    }
+
+  } else if (lm == layer_mode_selected) {
+
+    auto sel = view ()->selected_layers ();
+    for (auto s = sel.begin (); s != sel.end (); ++s) {
+
+      auto l = *s;
+      if (! l->has_children ()) {
+
+        int cvi = (l->cellview_index () >= 0) ? l->cellview_index () : 0;
+        lay::CellView ccv = view ()->cellview (cvi);
+        int li = l->layer_index ();
+
+        if (ccv.is_valid () || li >= 0 || ! ccv->layout ().is_valid_layer (li)) {
+          par.input_layers.push_back (std::make_pair (cvi, li));
+        }
+
+      }
+
+    }
+
+  }
+
+  //  Commit the parameters
+  dispatcher ()->config_set (cfg_density_map_layer_mode, lm);
+  dispatcher ()->config_set (cfg_density_map_region_mode, rm);
+  dispatcher ()->config_set (cfg_density_map_boundary_mode, par.boundary_mode);
+  dispatcher ()->config_set (cfg_density_map_threads, tl::to_string (par.threads));
+  dispatcher ()->config_set (cfg_density_map_pixel_size, tl::to_string (par.pixel_size));
+  dispatcher ()->config_set (cfg_density_map_window_size, tl::to_string (par.window_size));
+
+  if (lm == layer_mode_specific) {
+    dispatcher ()->config_set (cfg_density_map_source_layer, source_layer.to_string ());
+  }
+
+  if (rm == region_mode_layer_bbox) {
+    dispatcher ()->config_set (cfg_density_map_box_layer, region_layer.to_string ());
+  } else if (rm == region_mode_single_box) {
+    dispatcher ()->config_set (cfg_density_map_single_box, par.region.to_string ());
+  }
+
+  dispatcher ()->config_setup ();
+
+  compute_density_map (par);
+}
+
+void
+DensityMapDialog::compute_density_map (const DensityMapParameters &par)
+{
+  if (par.region.empty ()) {
+    throw tl::Exception (tl::to_string (QObject::tr ("Density map region is empty")));
+  }
+
+  if (par.input_layers.empty ()) {
+    throw tl::Exception (tl::to_string (QObject::tr ("No input layers given")));
+  }
+
+  //  Compute the tile origins
+
+  const double max_wh = 100000.0;
+  const int max_pixels = 100000000;
+
+  double dnx = std::max (1.0, ceil (par.region.width () / par.pixel_size - db::epsilon));
+  double dny = std::max (1.0, ceil (par.region.height () / par.pixel_size - db::epsilon));
+  if (dnx > max_wh || dny > max_wh) {
+    throw tl::Exception (tl::sprintf (tl::to_string (QObject::tr ("Density map dimensions exceed maximum limit of %g pixels in one direction"))), max_wh);
+  }
+
+  int nx = int (dnx);
+  int ny = int (dny);
+  if (dnx * dny > max_pixels) {
+    throw tl::Exception (tl::sprintf (tl::to_string (QObject::tr ("Density map array exceed maximum limit of %d pixels in total"))), max_pixels);
+  }
+
+  double x0 = par.region.center ().x () - nx * 0.5 * par.pixel_size;
+  double y0 = par.region.center ().y () - ny * 0.5 * par.pixel_size;
+
+  double dbu = view ()->cellview (par.input_layers.front ().first)->layout ().dbu ();
+
+  //  Set up the tiling processor
+
+  db::TilingProcessor tp;
+
+  tp.tiles (nx, ny);
+  tp.tile_origin (x0, y0);
+  tp.tile_size (par.pixel_size, par.pixel_size);
+
+  tp.set_threads (par.threads);
+  tp.set_dbu (dbu);
+
+  int ninput = 1;
+  std::string in_expr;
+
+  for (auto i = par.input_layers.begin (); i != par.input_layers.end (); ++i, ++ninput) {
+
+    const lay::CellView &cv = view ()->cellview (i->first);
+    const db::Layout &ly = cv->layout ();
+    const db::Cell &cell = ly.cell (cv.cell_index ());
+
+    std::string in_name = "in" + tl::to_string (ninput);
+    tp.input (in_name, db::RecursiveShapeIterator (ly, cell, i->second, true), db::ICplxTrans (ly.dbu () / dbu), db::TilingProcessor::TypeRegion, true);
+
+    if (! in_expr.empty ()) {
+      in_expr += "+";
+    }
+    in_expr += in_name;
+
+  }
+
+  tp.queue (std::string ("var inp = ") + in_expr + "; _tile && _output(dens, to_f(inp.area(_tile.bbox)) / to_f(_tile.bbox.area))");
+
+  //  Prepare the Image for receiving
+
+  img::Object *img_object = 0;
+
+  img::Service *img_service = view ()->get_plugin <img::Service> ();
+  if (img_service) {
+
+    const std::string img_tag = "density-map-image";
+
+    img::DataMapping dm;
+    dm.false_color_nodes.clear ();
+
+    //  default mapping blue -> red
+    //  TODO: we could use that from a previous image ...
+    dm.false_color_nodes.push_back (std::make_pair (0.0, std::make_pair (0x0000ff, 0x0000ff)));
+    dm.false_color_nodes.push_back (std::make_pair (1.0, std::make_pair (0xff0000, 0xff0000)));
+
+    for (auto i = img_service->begin_images (); ! i.at_end (); ++i) {
+      if (i->tag () == img_tag) {
+        //  inherit data mapping from previous image
+        dm = i->data_mapping ();
+        img_service->erase_image_by_id (i->id ());
+        break;
+      }
+    }
+
+    img::Object img (nx, ny, db::DCplxTrans (par.pixel_size, 0.0, false, par.region.center () - db::DPoint ()), false, false);
+    img.set_data_mapping (dm);
+    img.set_tag (img_tag);
+
+    img_object = img_service->insert_image (img);
+
+  }
+
+  tl_assert (img_object);
+  tp.output ("dens", 0, new DensityMapTileReceiver (img_object), db::ICplxTrans ());
+
+  //  Execute the tiling processor
+
+  tp.execute (tl::to_string (tr ("Computing density map")));
+
+  //  Do the averaging if requested
+
+  unsigned int nw = (unsigned int) (std::max (0.0, std::min (1000.0, floor (par.window_size / par.pixel_size + 0.5))));
+
+  if (nw > 1) {
+    average_window (*img_object, par.boundary_mode, nw);
+  }
+}
+
+inline int safe_mod (int a, int b)
+{
+  if (a < 0) {
+    return b - (-a % b);
+  } else {
+    return a % b;
+  }
+}
+
+void
+DensityMapDialog::average_window (img::Object &img_object, const std::string boundary_mode, int nw)
+{
+  bool periodic = (boundary_mode == boundary_mode_periodic);
+
+  int nx = img_object.width ();
+  int ny = img_object.height ();
+
+  //  compute the outside value if not periodic
+  double outside = 0.0;
+  if (boundary_mode == boundary_mode_one) {
+
+    outside = 1.0;
+
+  } else if (boundary_mode == boundary_mode_average) {
+
+    double outside = 0.0;
+    const float *d = img_object.float_data ();
+    for (size_t i = size_t (nx) * size_t (ny); i > 0; --i) {
+      outside += *d++;
+    }
+    outside /= double (nx) * double (ny);
+
+  }
+
+  std::vector<double> vavg_data;
+  vavg_data.resize (size_t (nx) * size_t (ny), 0.0);
+
+  //  vertical sum
+
+  for (int y = 0; y < ny; ++y) {
+
+    int wh = nw / 2;
+    double fb = (nw % 2 == 0) ? 0.5 : 1.0;
+
+    for (int dy = -wh; dy <= wh; ++dy) {
+
+      //  top and bottom row count half in case of even nw
+      double f = (dy == -wh || dy == wh) ? fb : 1.0;
+
+      std::vector<double>::iterator d = vavg_data.begin () + y * nx;
+      if (periodic || (y + dy >= 0 && y + dy < ny)) {
+        const float *s = img_object.float_data () + safe_mod (y + dy, ny) * nx;
+        for (int ix = 0; ix < nx; ++ix) {
+          *d++ += f * *s++;
+        }
+      } else {
+        for (int ix = 0; ix < nx; ++ix) {
+          *d++ += f * outside;
+        }
+      }
+
+    }
+
+  }
+
+  //  horizontal sum
+
+  outside *= nw;   //  because we do normalization later
+
+  //  TODO: transposing the image would make things more efficient
+
+  std::vector<double> havg_data;
+  havg_data.resize (size_t (nx) * size_t (ny), 0.0);
+
+  for (int x = 0; x < nx; ++x) {
+
+    int wh = nw / 2;
+    double fb = (nw % 2 == 0) ? 0.5 : 1.0;
+
+    for (int dx = -wh; dx <= wh; ++dx) {
+
+      //  top and bottom row count half in case of even nw
+      double f = (dx == -wh || dx == wh) ? fb : 1.0;
+
+      std::vector<double>::iterator d = havg_data.begin () + x;
+
+      if (periodic || (x + dx >= 0 && x + dx < nx)) {
+        std::vector<double>::const_iterator s = vavg_data.begin () + safe_mod (x + dx, nx);
+        for (int iy = 0; iy < ny; ++iy) {
+          *d += f * *s;
+          d += nx;
+          s += nx;
+        }
+      } else {
+        for (int iy = 0; iy < ny; ++iy) {
+          *d += f * outside;
+          d += nx;
+        }
+      }
+
+    }
+
+  }
+
+  //  take the average
+  double s = 1.0 / (double (nw) * double (nw));
+  for (auto i = havg_data.begin (); i != havg_data.end (); ++i) {
+    *i *= s;
+  }
+
+  img_object.set_data (nx, ny, havg_data);
+}
+
+}
+
diff --git a/src/plugins/tools/density_map/lay_plugin/layDensityMapDialog.h b/src/plugins/tools/density_map/lay_plugin/layDensityMapDialog.h
new file mode 100644
index 000000000..bd99bbbe8
--- /dev/null
+++ b/src/plugins/tools/density_map/lay_plugin/layDensityMapDialog.h
@@ -0,0 +1,98 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2026 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+
+#ifndef HDR_layDensityMapDialog
+#define HDR_layDensityMapDialog
+
+#include "ui_DensityMapDialog.h"
+
+#include "layLayoutView.h"
+#include "layBrowser.h"
+#include "layMarker.h"
+
+namespace img
+{
+  class Object;
+}
+
+namespace lay
+{
+
+class DensityMapDialog
+  : public lay::Browser,
+    private Ui::DensityMapDialog
+{
+Q_OBJECT 
+
+public:
+  DensityMapDialog (lay::Dispatcher *root, lay::LayoutViewBase *view);
+  ~DensityMapDialog ();
+
+public slots:
+  void layer_mode_changed (int);
+  void region_mode_changed (int);
+  void accept ();
+  void apply ();
+
+private:
+  struct DensityMapParameters
+  {
+    DensityMapParameters ()
+      : pixel_size (100.0), threads (1)
+    { }
+
+    //  Collects all cv_index/layer index pairs used for input
+    std::vector<std::pair<unsigned int, unsigned int> > input_layers;
+
+    //  The region to compute the density map from
+    db::DBox region;
+
+    //  The pixel size
+    double pixel_size;
+
+    //  The window size or zero for "no window"
+    double window_size;
+
+    //  The boundary mode
+    std::string boundary_mode;
+
+    //  The number of threads to use
+    int threads;
+  };
+
+  //  implementation of the lay::Plugin interface
+  virtual bool configure (const std::string &name, const std::string &value);
+
+  //  implementation of the lay::Plugin interface
+  void menu_activated (const std::string &symbol);
+
+  void make_density_map ();
+  void compute_density_map (const DensityMapParameters &par);
+  void average_window (img::Object &img_object, const std::string boundary_mode, int nw);
+
+};
+
+}
+
+#endif
+
diff --git a/src/plugins/tools/density_map/lay_plugin/lay_plugin.pro b/src/plugins/tools/density_map/lay_plugin/lay_plugin.pro
new file mode 100644
index 000000000..a448da1fe
--- /dev/null
+++ b/src/plugins/tools/density_map/lay_plugin/lay_plugin.pro
@@ -0,0 +1,18 @@
+
+TARGET = density_map_ui
+DESTDIR = $$OUT_PWD/../../../../lay_plugins
+
+include($$PWD/../../../lay_plugin.pri)
+
+INCLUDEPATH += $$IMG_INC $$ANT_INC
+DEPENDPATH += $$IMG_INC $$ANT_INC
+LIBS += -L$$DESTDIR/.. -lklayout_img -lklayout_ant
+
+HEADERS = \
+  layDensityMapDialog.h \
+
+SOURCES = \
+  layDensityMapDialog.cc \
+
+FORMS = \
+  DensityMapDialog.ui \
diff --git a/src/rdb/rdb/rdb.cc b/src/rdb/rdb/rdb.cc
index 475f310e4..367b25f5d 100644
--- a/src/rdb/rdb/rdb.cc
+++ b/src/rdb/rdb/rdb.cc
@@ -1920,13 +1920,15 @@ static void map_databases (rdb::Database &self, const rdb::Database &other,
                            std::map<id_type, id_type> &rev_tag2tag,
                            bool create_missing)
 {
+  std::list<std::pair<rdb::Cell *, const rdb::Cell *> > new_cells;
+
   for (auto c = other.cells ().begin (); c != other.cells ().end (); ++c) {
     //  TODO: do we have a consistent scheme of naming variants? What requirements
     //  exist towards detecting variant specific waivers
     rdb::Cell *this_cell = self.cell_by_qname_non_const (c->qname ());
     if (! this_cell && create_missing) {
       this_cell = self.create_cell (c->name (), c->variant (), c->layout_name ());
-      this_cell->import_references (c->references ());
+      new_cells.push_back (std::make_pair (this_cell, c.operator-> ()));
     }
     if (this_cell) {
       cell2cell.insert (std::make_pair (this_cell->id (), c->id ()));
@@ -1934,6 +1936,19 @@ static void map_databases (rdb::Database &self, const rdb::Database &other,
     }
   }
 
+  //  import and map references for new cells
+  for (auto cp = new_cells.begin (); cp != new_cells.end (); ++cp) {
+    auto &new_refs = cp->first->references ();
+    for (auto r = cp->second->references ().begin (); r != cp->second->references ().end (); ++r) {
+      rdb::Reference rnew = *r;
+      auto cid = rev_cell2cell.find (rnew.parent_cell_id ());
+      if (cid != rev_cell2cell.end ()) {
+        rnew.set_parent_cell_id (cid->second);
+        new_refs.insert (rnew);
+      }
+    }
+  }
+
   for (auto c = other.categories ().begin (); c != other.categories ().end (); ++c) {
     map_category (*c, self, cat2cat, rev_cat2cat, create_missing, 0);
   }
diff --git a/src/rdb/unit_tests/rdbTests.cc b/src/rdb/unit_tests/rdbTests.cc
index 4ccc25a08..814e73573 100644
--- a/src/rdb/unit_tests/rdbTests.cc
+++ b/src/rdb/unit_tests/rdbTests.cc
@@ -979,16 +979,18 @@ TEST(22_MergeCells)
   }
 
   {
+    rdb::Cell *cell1, *cell2, *cell3;
+    cell1 = db2.create_cell ("B");
+    cell2 = db2.create_cell ("A");
+    cell3 = db2.create_cell ("A", "VAR2", "ALAY");
+
+    //  NOTE: db2 parent is at a different position (issue #2339)
     rdb::Cell *parent;
     parent = db2.create_cell ("TOP");
 
-    rdb::Cell *cell;
-    cell = db2.create_cell ("B");
-    cell->references ().insert (rdb::Reference (db::DCplxTrans (db::DVector (1.0, 0.0)), parent->id ()));
-    cell = db2.create_cell ("A");
-    cell->references ().insert (rdb::Reference (db::DCplxTrans (db::DVector (1.0, 2.5)), parent->id ()));  //  reference not taken!
-    cell = db2.create_cell ("A", "VAR2", "ALAY");
-    cell->references ().insert (rdb::Reference (db::DCplxTrans (db::DVector (1.0, -1.0)), parent->id ()));
+    cell1->references ().insert (rdb::Reference (db::DCplxTrans (db::DVector (1.0, 0.0)), parent->id ()));
+    cell2->references ().insert (rdb::Reference (db::DCplxTrans (db::DVector (1.0, 2.5)), parent->id ()));  //  reference not taken as cell will be taken from db1
+    cell3->references ().insert (rdb::Reference (db::DCplxTrans (db::DVector (1.0, -1.0)), parent->id ()));
   }
 
   db1.merge (db2);
@@ -996,13 +998,13 @@ TEST(22_MergeCells)
   std::set<std::string> cells;
   for (auto c = db1.cells ().begin (); c != db1.cells ().end (); ++c) {
     if (c->references ().begin () != c->references ().end ()) {
-      cells.insert (c->qname () + "[" + c->references ().begin ()->trans_str () + "]");
+      cells.insert (c->qname () + "[" + c->references ().begin ()->trans_str () + ":" + db1.cell_by_id (c->references ().begin ()->parent_cell_id ())->qname () + "]");
     } else {
       cells.insert (c->qname ());
     }
   }
 
-  EXPECT_EQ (tl::join (cells.begin (), cells.end (), ";"), "A:1[r0 *1 1,2];A:VAR1[r0 *1 1,-2];A:VAR2[r0 *1 1,-1];B[r0 *1 1,0];TOP");
+  EXPECT_EQ (tl::join (cells.begin (), cells.end (), ";"), "A:1[r0 *1 1,2:TOP];A:VAR1[r0 *1 1,-2:TOP];A:VAR2[r0 *1 1,-1:TOP];B[r0 *1 1,0:TOP];TOP");
 }
 
 TEST(23_MergeTags)
diff --git a/testdata/drc/drcSimpleTests_au121.gds b/testdata/drc/drcSimpleTests_au121.gds
index 5476d6713..e873870f5 100644
Binary files a/testdata/drc/drcSimpleTests_au121.gds and b/testdata/drc/drcSimpleTests_au121.gds differ
diff --git a/testdata/lvs/split_substrate.cir b/testdata/lvs/split_substrate.cir
new file mode 100644
index 000000000..c6971c69e
--- /dev/null
+++ b/testdata/lvs/split_substrate.cir
@@ -0,0 +1,13 @@
+* Extracted by KLayout
+
+.SUBCKT TOP A Q IOSUB SUBSTRATE
+X$1 \$7 \$1 Q IOSUB IOSUB INV
+X$2 \$7 A \$1 SUBSTRATE SUBSTRATE INV
+.ENDS TOP
+
+.SUBCKT INV \$2 \$4 \$5 \$1 \$I11
+M$1 \$2 \$4 \$5 \$2 PMOS L=0.25U W=0.95U AS=0.73625P AD=0.73625P PS=3.45U
++ PD=3.45U
+M$2 \$1 \$4 \$5 \$I11 NMOS L=0.25U W=0.95U AS=0.73625P AD=0.73625P PS=3.45U
++ PD=3.45U
+.ENDS INV
diff --git a/testdata/lvs/split_substrate.gds b/testdata/lvs/split_substrate.gds
new file mode 100644
index 000000000..e33ad4d0b
Binary files /dev/null and b/testdata/lvs/split_substrate.gds differ
diff --git a/testdata/lvs/split_substrate.l2n b/testdata/lvs/split_substrate.l2n
new file mode 100644
index 000000000..95cb99951
--- /dev/null
+++ b/testdata/lvs/split_substrate.l2n
@@ -0,0 +1,215 @@
+#%l2n-klayout
+W(TOP)
+U(0.001)
+L(l3 '1/0')
+L(l4 '3/0')
+L(l15 '3/1')
+L(l8 '4/0')
+L(l11 '5/0')
+L(l12 '6/0')
+L(l16 '6/1')
+L(l13 '7/0')
+L(l14 '8/0')
+L(l17)
+L(l22 '10/0')
+L(l7)
+L(l10)
+L(l2)
+L(l9)
+L(l6)
+L(l21)
+L(l18)
+L(l20)
+L(l19)
+C(l3 l3 l10)
+C(l4 l4 l15 l11)
+C(l15 l4 l15)
+C(l8 l8 l12 l10 l2 l9 l6)
+CS(l8 l10 l2 l9 l6)
+C(l11 l4 l11 l12)
+CS(l11 l4)
+C(l12 l8 l11 l12 l16 l13)
+C(l16 l12 l16)
+C(l13 l12 l13 l14)
+C(l14 l13 l14 l17)
+C(l17 l14 l17)
+C(l22 l22 l21 l20)
+C(l7 l7 l18 l20)
+C(l10 l3 l8 l10)
+CS(l10 l3)
+C(l2 l8 l2)
+C(l9 l8 l9 l21 l19)
+C(l6 l8 l6)
+C(l21 l22 l9 l21)
+CS(l21 l22)
+C(l18 l7 l18)
+C(l20 l22 l7 l20)
+C(l19 l9 l19)
+G(l22 IOSUB)
+G(l18 SUBSTRATE)
+G(l19 SUBSTRATE)
+GS(l19 SUBSTRATE)
+H(W B('Net with incomplete wiring (soft-connected partial nets)') C(TOP) X('soft-connection-check'))
+H(B('\tPartial net #1: TOP/INV[r0 3,1.6]:$1 - $2') C(TOP) Q('(1.5,3.95;1.5,4.85;5.3,4.85;5.3,3.95)'))
+H(B('\tPartial net #2: TOP/INV[r0 7.7,1.6]:$2 - $2') C(TOP) Q('(6.2,3.95;6.2,4.85;10,4.85;10,3.95)'))
+K(PMOS MOS4)
+K(NMOS MOS4)
+D(D$PMOS PMOS
+ T(S
+  R(l2 (-900 -475) (775 950))
+ )
+ T(G
+  R(l4 (-125 -475) (250 950))
+ )
+ T(D
+  R(l2 (125 -475) (775 950))
+ )
+ T(B
+  R(l3 (-125 -475) (250 950))
+ )
+)
+D(D$NMOS NMOS
+ T(S
+  R(l6 (-900 -475) (775 950))
+ )
+ T(G
+  R(l4 (-125 -475) (250 950))
+ )
+ T(D
+  R(l6 (125 -475) (775 950))
+ )
+ T(B
+  R(l7 (-125 -475) (250 950))
+ )
+)
+X(INV
+ R((-1500 -800) (3800 4600))
+ N(1 I($1)
+  R(l8 (1700 100) (200 200))
+  R(l8 (-200 -600) (200 200))
+  R(l8 (-1610 -210) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l12 (890 -760) (800 900))
+  R(l12 (-1980 -830) (360 760))
+  R(l13 (-305 -705) (250 250))
+  R(l13 (-250 150) (250 250))
+  R(l13 (1175 -225) (200 200))
+  R(l13 (-200 -600) (200 200))
+  R(l14 (-3400 -350) (3000 900))
+  R(l14 (-200 -900) (1000 900))
+  R(l9 (-700 -950) (400 1000))
+  R(l6 (-1875 -975) (775 950))
+ )
+ N(2 I($2)
+  R(l3 (-1500 1800) (3000 2000))
+  R(l3 (-200 -2000) (1000 2000))
+  R(l8 (-2010 -1310) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l8 (1190 -210) (200 200))
+  R(l8 (-200 -600) (200 200))
+  R(l12 (-1680 -280) (360 760))
+  R(l12 (820 -830) (800 900))
+  R(l13 (-1925 -775) (250 250))
+  R(l13 (-250 150) (250 250))
+  R(l13 (1175 -225) (200 200))
+  R(l13 (-200 -600) (200 200))
+  R(l14 (-3400 -350) (3000 900))
+  R(l14 (-200 -900) (1000 900))
+  R(l10 (-700 -950) (400 1000))
+  R(l2 (-1875 -975) (775 950))
+ )
+ N(3 I($4)
+  R(l4 (-125 -250) (250 2500))
+  R(l4 (-250 -3050) (250 1600))
+  R(l4 (-250 1200) (250 1600))
+ )
+ N(4 I($5)
+  R(l8 (-510 -310) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l8 (-220 2180) (220 220))
+  R(l8 (-220 180) (220 220))
+  R(l12 (-290 -3530) (360 2840))
+  R(l12 (-360 -2800) (360 760))
+  R(l12 (-360 2040) (360 760))
+  R(l2 (-680 -855) (775 950))
+  R(l6 (-775 -3750) (775 950))
+ )
+ N(5 I($I11))
+ P(2)
+ P(3)
+ P(4)
+ P(1)
+ P(5)
+ D(1 D$PMOS
+  Y(0 2800)
+  E(L 0.25)
+  E(W 0.95)
+  E(AS 0.73625)
+  E(AD 0.73625)
+  E(PS 3.45)
+  E(PD 3.45)
+  T(S 4)
+  T(G 3)
+  T(D 2)
+  T(B 2)
+ )
+ D(2 D$NMOS
+  Y(0 0)
+  E(L 0.25)
+  E(W 0.95)
+  E(AS 0.73625)
+  E(AD 0.73625)
+  E(PS 3.45)
+  E(PD 3.45)
+  T(S 4)
+  T(G 3)
+  T(D 1)
+  T(B 5)
+ )
+)
+X(TOP
+ R((1334 621) (9246 5073))
+ N(1 I($1)
+  R(l4 (2920 2600) (3980 400))
+  R(l11 (-300 -300) (200 200))
+  R(l12 (-300 -300) (690 400))
+ )
+ N(2 I(A)
+  R(l4 (7700 2600) (2880 400))
+  R(l15 (-2380 -200) (0 0))
+ )
+ N(3 I(Q)
+  R(l12 (1810 2600) (690 400))
+  R(l16 (-400 -200) (0 0))
+ )
+ N(4 I(IOSUB)
+  R(l22 (1334 621) (4230 5073))
+  R(l21 (-964 -4594) (400 1000))
+  R(l20 (-2125 -975) (250 950))
+ )
+ N(5 I($7)
+  R(l3 (4000 3400) (2700 2000))
+ )
+ N(6 I(SUBSTRATE)
+  R(l18 (7575 1125) (250 950))
+  R(l19 (1475 -975) (400 1000))
+ )
+ P(2 I(A))
+ P(3 I(Q))
+ P(4 I(IOSUB))
+ P(6 I(SUBSTRATE))
+ X(1 INV Y(3000 1600)
+  P(0 5)
+  P(1 1)
+  P(2 3)
+  P(3 4)
+  P(4 4)
+ )
+ X(2 INV Y(7700 1600)
+  P(0 5)
+  P(1 2)
+  P(2 1)
+  P(3 6)
+  P(4 6)
+ )
+)
diff --git a/testdata/lvs/split_substrate.lvs b/testdata/lvs/split_substrate.lvs
new file mode 100644
index 000000000..43204067d
--- /dev/null
+++ b/testdata/lvs/split_substrate.lvs
@@ -0,0 +1,107 @@
+
+$lvs_test_source && source($lvs_test_source)
+
+if $lvs_test_target_l2n
+  report_netlist($lvs_test_target_l2n)
+else
+  report_netlist
+end
+
+writer = write_spice(true, false)
+$lvs_test_target_cir && target_netlist($lvs_test_target_cir, writer, "Extracted by KLayout")
+
+deep
+
+# Drawing layers
+
+nwell       = input(1, 0)
+active      = input(2, 0)
+nplus       = input(2, 1)
+pplus       = input(2, 2)
+poly        = input(3, 0)
+poly_lbl    = input(3, 1)
+diff_cont   = input(4, 0)
+poly_cont   = input(5, 0)
+metal1      = input(6, 0)
+metal1_lbl  = input(6, 1)
+via1        = input(7, 0)
+metal2      = input(8, 0)
+metal2_lbl  = input(8, 1)
+iosub       = input(10, 0)
+
+# Bulk layer for terminal provisioning
+
+bulk        = polygon_layer
+
+psd = nil
+nsd = nil
+
+# Computed layers
+
+active_in_nwell       = active & nwell
+pactive               = active_in_nwell & pplus
+ntie                  = active_in_nwell & nplus
+pgate                 = pactive & poly
+psd                   = pactive - pgate
+
+active_outside_nwell  = active - nwell
+nactive               = active_outside_nwell & nplus
+ptie                  = active_outside_nwell & pplus
+ngate                 = nactive & poly
+nsd                   = nactive - ngate
+
+# Device extraction
+
+# PMOS transistor device extraction
+extract_devices(mos4("PMOS"), { "SD" => psd, "G" => pgate, "W" => nwell,
+                                "tS" => psd, "tD" => psd, "tG" => poly })
+
+# NMOS transistor device extraction
+extract_devices(mos4("NMOS"), { "SD" => nsd, "G" => ngate, "W" => bulk,
+                                "tS" => nsd, "tD" => nsd, "tG" => poly })
+
+# Define connectivity for netlist extraction
+
+# Inter-layer
+
+soft_connect(diff_cont, psd)
+soft_connect(diff_cont, nsd)
+soft_connect(diff_cont, ptie)
+soft_connect(diff_cont, ntie)
+soft_connect(ntie, nwell)
+soft_connect(poly_cont, poly)
+
+connect(diff_cont, metal1)
+connect(poly_cont, metal1)
+connect(metal1, via1)
+connect(via1, metal2)
+
+# attach labels
+connect(poly, poly_lbl)
+connect(metal1, metal1_lbl)
+connect(metal2, metal2_lbl)
+
+# Split bulk and ptie into inside and outside iosub
+(bulk_io, bulk_reg) = bulk.andnot(iosub)
+(ptie_io, ptie_reg) = ptie.andnot(iosub)
+
+# connect outside to "SUBSTRATE" globally
+connect(bulk, bulk_reg)
+connect(ptie, ptie_reg)
+connect_global(bulk_reg, "SUBSTRATE")
+soft_connect_global(ptie_reg, "SUBSTRATE")
+
+# connect inside to "IOSUB" via polygons
+connect(bulk, bulk_io)
+connect(ptie, ptie_io)
+connect(bulk_io, iosub)
+soft_connect(ptie_io, iosub)
+connect_global(iosub, "IOSUB")
+
+# Netlist section (NOTE: we only check log here)
+# for debugging: _make_soft_connection_diodes(true)
+netlist
+
+netlist.simplify
+
+